Windows 7 Ultimate's XP Mode and 32 bit Windows 7 computers are the ones where you'll have AkSys crash. One's a total emulated OS and the latter is definitely having some issue with something in the USB stack changing from 98/XP as it's always a USB disconnect error.
These were my personal experiences with 2 Windows 7 computers I have, on an XP or '98 install AkSys works fine. On OS X I know you have to have an older OS revision to run AkSys, but some people here reported better stability with vmware running Windows on OS X. Their results sounded a lot better than what I encountered using a native Windows virtual OS. (Or run a virtual Snow Leopard...)
Coz is dead on about the USB port. You can always just load the whole machine's memory from the stick and save it all to the internal HD. I actually had covered that port using a quicklock stand for a while, won't be covering it up again.
