Fez Spider keeps disconnecting/reconnecting on USB

hello everybody,
i had everything working, 2 months ago (My Fez Spider connected over USB with NETMF 4.3 and Visual Studio 2012). My demos worked, etc.
Recently I reinstalled my machine (same machine), and with Windows 8.1 and I cannot seem to keep my device connected to my computer over USB.

When I connect, I hear the USB connection noise and around 5 seconds later, I hear the USB disconnecting noise. And that happens in a constant loop. With FezConfig, I see the device appearing and disappearing too.
Tried reinstalling USB drivers, rebooting, etc.

I’m out of ideas and this is my last hope for getting everything up & running again for my talk on thursday. Any ideas ?

Cheers

Hello Andre,
Thanks for your prompt reply!
I’m running 4.3 and the device is still running a program I wrote 2-3 months ago.
Anyway, I now switched to a powered USB hub I had laying around and it seems to be working, so probably the device didn’t have enough power.
Would you know a reason why the previous set-up used to work back then and no longer now?
Anyway, the problem is solved on my side now.