S3 Woes

I had S3 working on my laptop for a while, and now it will not resume if any USB devices are plugged in. It doesn't mind the bus drivers (uhci-hcd and ehci-hcd), and it doesn't seem to mind the device drivers themselves being present (usb-storage, hid usually), but if there's a USB device plugged into this laptop, the laptop powers on, asks for my BIOS password, and then goes blank. Caps/Num/Scroll Lock work for a short period, and then the whole machine appears to freeze (of course there's no good way to know for absolute sure, but if Caps Lock doesn't work then there's a definite problem :)). Anyone know why this is happening, or more importantly what could have changed (most likely in kernel config) to cause this to happen? Preempt is off.

--
Andrew Barr

/usr/games/fortune says:
If Karl, instead of writing a lot about Capital, had made a lot of Capital, it would have been much better.
-- Karl Marx's Mother