I think it´s a problem by Screenshot Captor. I tried several other programs with autoscroll feature: Hypersnap 6.50.03, FastStone Capture 6.3, Ashampoo Snap 3 and SnagIt 9.12. All of these programs have no difficulties in Autoscrolling neither in Firefox 3 nor in IE 8. The problem seems for me, that Screenshot capture does not move the scrollbar, and therefore you get always a capture of the visible window. I hope that there will be a solution for this problem.