diff --git a/oscar/SleepLib/loader_plugins/prs1_loader.cpp b/oscar/SleepLib/loader_plugins/prs1_loader.cpp
index 62ab8f0d..8dfaca59 100644
--- a/oscar/SleepLib/loader_plugins/prs1_loader.cpp
+++ b/oscar/SleepLib/loader_plugins/prs1_loader.cpp
@@ -93,6 +93,102 @@ static crc16_t CRC16(unsigned char * data, size_t data_len, crc16_t crc=0)
 }
 
 
+// CRC-32/MPEG-2, polynomial: 0x104C11DB7
+// Table generated by crcmod (crc-32-mpeg)
+
+typedef quint32 crc32_t;
+static crc32_t CRC32(const unsigned char *data, size_t data_len, crc32_t crc=0xffffffffU)
+{
+    static const crc32_t table[256] = {
+    0x00000000U, 0x04c11db7U, 0x09823b6eU, 0x0d4326d9U,
+    0x130476dcU, 0x17c56b6bU, 0x1a864db2U, 0x1e475005U,
+    0x2608edb8U, 0x22c9f00fU, 0x2f8ad6d6U, 0x2b4bcb61U,
+    0x350c9b64U, 0x31cd86d3U, 0x3c8ea00aU, 0x384fbdbdU,
+    0x4c11db70U, 0x48d0c6c7U, 0x4593e01eU, 0x4152fda9U,
+    0x5f15adacU, 0x5bd4b01bU, 0x569796c2U, 0x52568b75U,
+    0x6a1936c8U, 0x6ed82b7fU, 0x639b0da6U, 0x675a1011U,
+    0x791d4014U, 0x7ddc5da3U, 0x709f7b7aU, 0x745e66cdU,
+    0x9823b6e0U, 0x9ce2ab57U, 0x91a18d8eU, 0x95609039U,
+    0x8b27c03cU, 0x8fe6dd8bU, 0x82a5fb52U, 0x8664e6e5U,
+    0xbe2b5b58U, 0xbaea46efU, 0xb7a96036U, 0xb3687d81U,
+    0xad2f2d84U, 0xa9ee3033U, 0xa4ad16eaU, 0xa06c0b5dU,
+    0xd4326d90U, 0xd0f37027U, 0xddb056feU, 0xd9714b49U,
+    0xc7361b4cU, 0xc3f706fbU, 0xceb42022U, 0xca753d95U,
+    0xf23a8028U, 0xf6fb9d9fU, 0xfbb8bb46U, 0xff79a6f1U,
+    0xe13ef6f4U, 0xe5ffeb43U, 0xe8bccd9aU, 0xec7dd02dU,
+    0x34867077U, 0x30476dc0U, 0x3d044b19U, 0x39c556aeU,
+    0x278206abU, 0x23431b1cU, 0x2e003dc5U, 0x2ac12072U,
+    0x128e9dcfU, 0x164f8078U, 0x1b0ca6a1U, 0x1fcdbb16U,
+    0x018aeb13U, 0x054bf6a4U, 0x0808d07dU, 0x0cc9cdcaU,
+    0x7897ab07U, 0x7c56b6b0U, 0x71159069U, 0x75d48ddeU,
+    0x6b93dddbU, 0x6f52c06cU, 0x6211e6b5U, 0x66d0fb02U,
+    0x5e9f46bfU, 0x5a5e5b08U, 0x571d7dd1U, 0x53dc6066U,
+    0x4d9b3063U, 0x495a2dd4U, 0x44190b0dU, 0x40d816baU,
+    0xaca5c697U, 0xa864db20U, 0xa527fdf9U, 0xa1e6e04eU,
+    0xbfa1b04bU, 0xbb60adfcU, 0xb6238b25U, 0xb2e29692U,
+    0x8aad2b2fU, 0x8e6c3698U, 0x832f1041U, 0x87ee0df6U,
+    0x99a95df3U, 0x9d684044U, 0x902b669dU, 0x94ea7b2aU,
+    0xe0b41de7U, 0xe4750050U, 0xe9362689U, 0xedf73b3eU,
+    0xf3b06b3bU, 0xf771768cU, 0xfa325055U, 0xfef34de2U,
+    0xc6bcf05fU, 0xc27dede8U, 0xcf3ecb31U, 0xcbffd686U,
+    0xd5b88683U, 0xd1799b34U, 0xdc3abdedU, 0xd8fba05aU,
+    0x690ce0eeU, 0x6dcdfd59U, 0x608edb80U, 0x644fc637U,
+    0x7a089632U, 0x7ec98b85U, 0x738aad5cU, 0x774bb0ebU,
+    0x4f040d56U, 0x4bc510e1U, 0x46863638U, 0x42472b8fU,
+    0x5c007b8aU, 0x58c1663dU, 0x558240e4U, 0x51435d53U,
+    0x251d3b9eU, 0x21dc2629U, 0x2c9f00f0U, 0x285e1d47U,
+    0x36194d42U, 0x32d850f5U, 0x3f9b762cU, 0x3b5a6b9bU,
+    0x0315d626U, 0x07d4cb91U, 0x0a97ed48U, 0x0e56f0ffU,
+    0x1011a0faU, 0x14d0bd4dU, 0x19939b94U, 0x1d528623U,
+    0xf12f560eU, 0xf5ee4bb9U, 0xf8ad6d60U, 0xfc6c70d7U,
+    0xe22b20d2U, 0xe6ea3d65U, 0xeba91bbcU, 0xef68060bU,
+    0xd727bbb6U, 0xd3e6a601U, 0xdea580d8U, 0xda649d6fU,
+    0xc423cd6aU, 0xc0e2d0ddU, 0xcda1f604U, 0xc960ebb3U,
+    0xbd3e8d7eU, 0xb9ff90c9U, 0xb4bcb610U, 0xb07daba7U,
+    0xae3afba2U, 0xaafbe615U, 0xa7b8c0ccU, 0xa379dd7bU,
+    0x9b3660c6U, 0x9ff77d71U, 0x92b45ba8U, 0x9675461fU,
+    0x8832161aU, 0x8cf30badU, 0x81b02d74U, 0x857130c3U,
+    0x5d8a9099U, 0x594b8d2eU, 0x5408abf7U, 0x50c9b640U,
+    0x4e8ee645U, 0x4a4ffbf2U, 0x470cdd2bU, 0x43cdc09cU,
+    0x7b827d21U, 0x7f436096U, 0x7200464fU, 0x76c15bf8U,
+    0x68860bfdU, 0x6c47164aU, 0x61043093U, 0x65c52d24U,
+    0x119b4be9U, 0x155a565eU, 0x18197087U, 0x1cd86d30U,
+    0x029f3d35U, 0x065e2082U, 0x0b1d065bU, 0x0fdc1becU,
+    0x3793a651U, 0x3352bbe6U, 0x3e119d3fU, 0x3ad08088U,
+    0x2497d08dU, 0x2056cd3aU, 0x2d15ebe3U, 0x29d4f654U,
+    0xc5a92679U, 0xc1683bceU, 0xcc2b1d17U, 0xc8ea00a0U,
+    0xd6ad50a5U, 0xd26c4d12U, 0xdf2f6bcbU, 0xdbee767cU,
+    0xe3a1cbc1U, 0xe760d676U, 0xea23f0afU, 0xeee2ed18U,
+    0xf0a5bd1dU, 0xf464a0aaU, 0xf9278673U, 0xfde69bc4U,
+    0x89b8fd09U, 0x8d79e0beU, 0x803ac667U, 0x84fbdbd0U,
+    0x9abc8bd5U, 0x9e7d9662U, 0x933eb0bbU, 0x97ffad0cU,
+    0xafb010b1U, 0xab710d06U, 0xa6322bdfU, 0xa2f33668U,
+    0xbcb4666dU, 0xb8757bdaU, 0xb5365d03U, 0xb1f740b4U,
+    };
+    
+    for (size_t i=0; i < data_len; i++) {
+        crc = table[(*data ^ (unsigned char)(crc >> 24)) & 0xFF] ^ (crc << 8);
+        data++;
+    }
+    return crc;
+}
+
+
+// Strangely, the PRS1 CRC32 appears to consider every byte a 32-bit wchar_t.
+// Nothing like trying a bunch of encodings and CRC32 variants on PROP.TXT files
+// until you find a winner.
+
+static crc32_t CRC32wchar(const unsigned char *data, size_t data_len, crc32_t crc=0xffffffffU)
+{
+    for (size_t i=0; i < data_len; i++) {
+        static unsigned char wch[4] = { 0, 0, 0, 0 };
+        wch[3] = *data++;
+        crc = CRC32(wch, 4, crc);
+    }
+    return crc;
+}
+
+
 enum FlexMode { FLEX_None, FLEX_CFlex, FLEX_CFlexPlus, FLEX_AFlex, FLEX_RiseTime, FLEX_BiFlex, FLEX_Unknown  };
 
 ChannelID PRS1_TimedBreath = 0, PRS1_HeatedTubing = 0;
@@ -821,6 +917,7 @@ void PRS1Loader::ScanFiles(const QStringList & paths, int sessionid_base, Machin
                 case 0:
                     if (task->compliance) {
                         qWarning() << path << "duplicate compliance?";
+                        delete chunk;
                         continue; // (skipping to avoid duplicates)
                     }
                     task->compliance = chunk;
@@ -828,6 +925,7 @@ void PRS1Loader::ScanFiles(const QStringList & paths, int sessionid_base, Machin
                 case 1:
                     if (task->summary) {
                         qWarning() << path << "duplicate summary?";
+                        delete chunk;
                         continue;
                     }
                     task->summary = chunk;
@@ -835,6 +933,7 @@ void PRS1Loader::ScanFiles(const QStringList & paths, int sessionid_base, Machin
                 case 2:
                     if (task->event) {
                         qWarning() << path << "duplicate events?";
+                        delete chunk;
                         continue;
                     }
                     task->event = chunk;
@@ -3517,7 +3616,7 @@ bool PRS1DataChunk::ReadHeader(QFile & f)
             break;
         }
         if (this->fileVersion < 2 || this->fileVersion > 3) {
-            qWarning() << this->m_path << "Never seen PRS1 header version < 2 or > 3 before";
+            qWarning() << this->m_path << "@" << hex << this->m_filepos << "Never seen PRS1 header version < 2 or > 3 before";
             break;
         }
 
@@ -3698,7 +3797,7 @@ bool PRS1DataChunk::ReadData(QFile & f)
             if (!ExtractStoredCrc(4)) {
                 break;
             }
-            this->calcCrc = this->storedCrc;  // TODO
+            this->calcCrc = CRC32wchar((unsigned char *)this->m_data.data(), this->m_data.size());
         } else {
             // The last 2 bytes contain a CRC16 checksum of the data.
             if (!ExtractStoredCrc(2)) {