Index: src/hg/js/hgTracks.js
===================================================================
RCS file: /projects/compbio/cvsroot/kent/src/hg/js/hgTracks.js,v
retrieving revision 1.42
retrieving revision 1.43
diff -b -B -U 4 -r1.42 -r1.43
--- src/hg/js/hgTracks.js	16 Sep 2009 17:34:00 -0000	1.42
+++ src/hg/js/hgTracks.js	16 Sep 2009 19:52:52 -0000	1.43
@@ -425,12 +425,12 @@
                 }
                 else if(mouseHasMoved) {
                     if( isWithin(-20,pxUp,chr.left) ) // bounded by chrom dimensions: but must remain within image!
                         pxUp = chr.left;
-                    if( isWithin(chr.right,pxUp,chr.right + 30) )
+                    if( isWithin(chr.right,pxUp,img.width + 20) )
                         pxUp = chr.right;
 
-                    if( isWithin(chr.left,pxUp,chr.right) ) {
+                    if( isWithin(chr.left,pxUp,chr.right+1) ) {
 
                         selRange.beg = convertToBases(pxDown);
                         selRange.end = convertToBases(pxUp);
 

