NSTextView not refreshed properly on scrolling

I have a NSTextView with a sizeable quantity of text. Whenever I scroll however, the view isn't updated properly. There are some artifacts that remain at the top or the bottom of the view. It appears that the view doesn't refresh itself often enough. If I scroll very slowly the view updates correctly though. If I add a border to the view everything works perfectly, borderless view is the one that has a problem. Here's a link to a screenshot:

Thanks

Have you set the setDrawsBackground and copiesOnScroll propertes for either the NSScrollView or the NSClipView?

The first thing I would suggest is turning off the "draws background" property of the NSScrollView:

[myScrollView setDrawsBackground:NO];

Note that this should be set on the NSScrollView, and not on the embedded NSClipView.

The following excerpt from the documentation may be relevant:

If your NSScrollView encloses an NSClipView sending a setDrawsBackground: message with a parameter of NO to the NSScrollView has the added effect of sending the NSClipView a setCopiesOnScroll: message with a parameter of NO. The side effect of sending the setDrawsBackground: message directly to the NSClipView instead would be the appearance of “trails” (vestiges of previous drawing) in the document view as it is scrolled.