Bitmaps Disappearing - $50 Reward

Hi there,

This thing has been bugging me forever. I have a drawing application where you can sketch stuff and draw various shapes. In order for the lines to be drawn properly with alpha, I had to use bitmaps (so at the points where lines are connected, there aren’t any darker circles). But this method brings a strange problem… After drawing the 24th line, the very first line disappears… Tracing some info on the Bitmap reveals that everything seems to be fine. If anyone can figure this out for me, I am willing to pay $50 (via paypal). You can find the source code at http://zylum.net/Sketcher.rar

Thanks,

Mike