diff --git a/Graphs/gFlagsLine.cpp b/Graphs/gFlagsLine.cpp
index 5521cdcc..1ed6941e 100644
--- a/Graphs/gFlagsLine.cpp
+++ b/Graphs/gFlagsLine.cpp
@@ -142,7 +142,7 @@ void gFlagsLine::Plot(gGraphWindow & w,float scrx,float scry)
 
     float top=floor(line_top)+2;
     float bottom=top+floor(line_h)-3;
-
+    bool verts_exceeded=false;
     qint64 X,Y;
     for (QVector<Session *>::iterator s=m_day->begin();s!=m_day->end(); s++) {
         if ((*s)->eventlist.find(m_code)==(*s)->eventlist.end()) continue;
@@ -160,6 +160,7 @@ void gFlagsLine::Plot(gGraphWindow & w,float scrx,float scry)
                 vertarray[vertcnt++]=top;
                 vertarray[vertcnt++]=x1;
                 vertarray[vertcnt++]=bottom;
+                if (vertcnt>maxverts) { verts_exceeded=true; break; }
             } else if (m_flt==FT_Span) {
                 x2=(Y-minx)*xmult+w.GetLeftMargin();
                 //w1=x2-x1;
@@ -171,9 +172,13 @@ void gFlagsLine::Plot(gGraphWindow & w,float scrx,float scry)
                 quadarray[quadcnt++]=bottom;
                 quadarray[quadcnt++]=x2;
                 quadarray[quadcnt++]=top;
+                if (quadcnt>maxverts) { verts_exceeded=true; break; }
             }
         }
     }
+    if (verts_exceeded) {
+        qWarning() << "maxverts exceeded in gFlagsLine::plot()";
+    }
     glScissor(w.GetLeftMargin(),w.GetBottomMargin(),width,height);
     glEnable(GL_SCISSOR_TEST);
 
diff --git a/Graphs/gLineOverlay.cpp b/Graphs/gLineOverlay.cpp
index e7d8e37a..be5de68d 100644
--- a/Graphs/gLineOverlay.cpp
+++ b/Graphs/gLineOverlay.cpp
@@ -53,6 +53,8 @@ void gLineOverlayBar::Plot(gGraphWindow & w,float scrx,float scry)
 
     double X;
     double Y;
+
+    bool verts_exceeded=false;
     QHash<ChannelID,QVector<EventList *> >::iterator cei;
     for (QVector<Session *>::iterator s=m_day->begin();s!=m_day->end(); s++) {
         cei=(*s)->eventlist.find(m_code);
@@ -61,7 +63,6 @@ void gLineOverlayBar::Plot(gGraphWindow & w,float scrx,float scry)
 
         EventList & el=*cei.value()[0];
 
-       // bool done=false;
         for (int i=0;i<el.count();i++) {
             X=el.time(i);
             if (m_flt==FT_Span) {
@@ -86,6 +87,7 @@ void gLineOverlayBar::Plot(gGraphWindow & w,float scrx,float scry)
                 quadarray[quadcnt++]=start_py+height;
                 quadarray[quadcnt++]=x2;
                 quadarray[quadcnt++]=start_py;
+                if (quadcnt>=maxverts) { verts_exceeded=true; break; }
             } else if (m_flt==FT_Dot) {
                 //if (pref["AlwaysShowOverlayBars"].toBool()) {
 
@@ -93,12 +95,15 @@ void gLineOverlayBar::Plot(gGraphWindow & w,float scrx,float scry)
                     // show the fat dots in the middle
                     pointarray[pointcnt++]=x1;
                     pointarray[pointcnt++]=w.y2p(20);
+                    if (pointcnt>=maxverts) { verts_exceeded=true; break; }
                 } else {
                     // thin lines down the bottom
                     vertarray[vertcnt++]=x1;
                     vertarray[vertcnt++]=start_py+1;
                     vertarray[vertcnt++]=x1;
                     vertarray[vertcnt++]=start_py+1+12;
+                    if (vertcnt>=maxverts) { verts_exceeded=true; break; }
+
                 }
             } else if (m_flt==FT_Bar) {
                 int z=start_py+height;
@@ -111,12 +116,14 @@ void gLineOverlayBar::Plot(gGraphWindow & w,float scrx,float scry)
                     vertarray[vertcnt++]=top;
                     vertarray[vertcnt++]=x1;
                     vertarray[vertcnt++]=bottom;
+                    if (pointcnt>=maxverts) { verts_exceeded=true; break; }
                } else {
                     vertarray[vertcnt++]=x1;
                     vertarray[vertcnt++]=z;
                     vertarray[vertcnt++]=x1;
                     vertarray[vertcnt++]=z-12;
                }
+               if (vertcnt>=maxverts) { verts_exceeded=true; break; }
                if (xx<(1800000)) {
                     GetTextExtent(m_label,x,y);
                     DrawText(w,m_label,x1-(x/2),scry-(start_py+height-30+y));
@@ -125,8 +132,10 @@ void gLineOverlayBar::Plot(gGraphWindow & w,float scrx,float scry)
 
            }
         }
-        if ((vertcnt>=maxverts) || (quadcnt>=maxverts) || (pointcnt>=maxverts)) break;
-
+        if (verts_exceeded) break;
+    }
+    if (verts_exceeded) {
+        qWarning() << "exceeded maxverts in gLineOverlay::Plot()";
     }
 
     bool antialias=pref["UseAntiAliasing"].toBool();
diff --git a/Graphs/gXAxis.cpp b/Graphs/gXAxis.cpp
index 628dff8d..52c3c7f4 100644
--- a/Graphs/gXAxis.cpp
+++ b/Graphs/gXAxis.cpp
@@ -125,7 +125,7 @@ void gXAxis::Plot(gGraphWindow & w,float scrx,float scry)
             vertarray[vertcnt++]=py;
             vertarray[vertcnt++]=px;
             vertarray[vertcnt++]=py-4;
-            if (vertcnt>maxverts) {
+            if (vertcnt>=maxverts) {
                 qWarning() << "gXAxis::Plot() maxverts exceeded trying to draw minor ticks";
                 return;
             }
@@ -173,7 +173,7 @@ void gXAxis::Plot(gGraphWindow & w,float scrx,float scry)
             vertarray[vertcnt++]=py;
             vertarray[vertcnt++]=px;
             vertarray[vertcnt++]=py-6;
-            if (vertcnt>maxverts) {
+            if (vertcnt>=maxverts) {
                 qWarning() << "gXAxis::Plot() maxverts exceeded trying to draw Major ticks";
                 return;
             }