fixed http://community.sharpdevelop.net/forums/p/11951/32716.aspx#32716

src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/VBNet/VBNetExpressionFinder.cs

@@ -26,7 +26,8 @@ namespace ICSharpCode.SharpDevelop.Dom.VBNet
 		
 		int LocationToOffset(Location location)
 		{
-			if (location.Line <= 0) return -1;
+			if (location.Line <= 0 || location.Line >= lineOffsets.Count)
+				return -1;
 			return lineOffsets[location.Line - 1] + location.Column - 1;
 		}