Black screen on boot up

I've been suffering with the black screen on boot up problem - it just
appeared overnight on a previously working install.

I've managed to (temporarily more than likely) solve the problem by
unplugging a number of USB devices which were, prior to physically moving
the PC, plugged in to different USB ports on the mobo. I had these USB
devices plugged in to these original ports when I installed Vista - the
problem started after moving the PC and plugging the devices in to different
ports. If I plug the USB devices in to the mobo and boot the PC Vista will
oftenboot to the black unresponsive desktop (just the mouse pointer on the
screen and nothing else). It seems possible that, for some reason, the black
screen is being caused on boot up by certain USB devices being connected to
ports different from the ones they were connected to when Vista was
installed.

Has MS given any indication that it is taking the black screen of death on
boot up seriously? I can find no solution or mention on the MS website
despite many posts to many forums describing the problem.

Gareth.