I doubt it, since it is not related to one system or one power supply.
If it is not the power supply or a loose connection of the Vampire to the Amiga mainboard, then it would seem your Vampire is faulty. On the recent cores like Gold 2 and 2.5 the Vampires are 100% stable unless, you know, the obvious: MMU and FPU software. You might want to contact your seller about the card.