I'm not sure of your terminology here - what do you mean by pause? Suspend is when you hit the || button. Shut down is when the guest OS actually shuts down.
I'm sure you already did, but might be worth manually verifying that you're on current release of Fusion, and have updated both the virtual hardware and VMWare tools in the guest.
Did you try, on the one that fails, to physically unplug the USB devices and plug them back into a different port? If you're using a hub you can just move that plug from one to another.