This problem is rendering my notebook nearly useless under Win7-64bit, yet it has been working flawlessly under WinXP-32bit.
Has anyone run into problems on 64-bit Windows7, with the FrontEnd zombie'ing-out with Windows' "Not Responding" (showing up on the title bar), when a Manipulate pauses to do some work? I have been using DynamicEvaluationTimeout->10000 in a Style wrapper around Manipulate. I've tried SynchronousUpdating->False without relief.
I'm using Mathematica 8.0.1 on both Win7-64bit laptop and my old WinXP-32bit desktop. All MSUpdates current. No other user programs running. Memory is not an issue. On Win7, when the Manipulate cell is under evaluation (cell bracket turns active), sometimes the darn cursor turns into the pesky Win7 rotating-donut, and the title bar shows "Not Responding" - sometimes it will recover and finish evaluation, but often not. And at least on this laptop, when it hangs, clicking into the window will "bleach" it (white level goes up).
Is there any dynamic evaluation option to try? OptionInspector?