It seems that every BitWise release has one "crisis" that rears its ugly head at some point. This beta's crisis deals with whiteboard redrawing on Windows and was brought to my attention thanks to [a new!] forum member. To reproduce the bug, make an object on the whiteboard that causes scrollbars to appear; the whiteboard will immediatelly begin to refresh like crazy. Not pretty at all, but fortunately relatively easy to fix. In the process, the logic for handling the scrollbars was also simplified and improved.
In the process of fixing the bug, I realized that I was still really unhappy with the flicker on the whiteboards when moving and creating an object. Try this experiment: make two large circles, and then use the select tool and drag one around the other. You'll see nasty tearing artifacts and flicker as you do this. By using the new wxBufferedDC class in wxWidgets 2.6, these unpleasant artifacts have been completely removed. I'm very pleased.
While I was at it, I added the ellipse drawing as well. The circle tool now will draw an ellipse, unless before starting drawing you hold down the Shift key, which will produce the classic circle. This change isn't backwards compatible; ellipses drawn using 1.0.5 will not appear on 1.0.4 or 1.0.5 Beta 1 whiteboards. Like the whiteboard changes in 1.0.4, I think this non-compatible change is acceptable in the name of progress.
Lastly, I am very pleased that the new icons in 1.0.5 Beta 1 seem to be a big hit. Some people have said the change is so impressive that it should be called BitWise Version 2! That's really saying a lot!
Sounds similar to the "ClipChildren" function in an edit box. Clips out all the busy refreshing going on in the window. Simple, but drives you mad until you find a fix.