Thats four cores back in the game.
For some bizzare reason Vista decided to chut itself down this evening, not a clue why (must check the logs...)
Anyway, took the opertunity to get the SMP core up and running again. So after several swaps between the user and admn accounts, it is now folding away. Re-installed the SMP client under XP on my media box, very easy. Although it did get confused by the old work unit sitting there incomplete and past its due date. Had to kill the 8 folding threads i had started by mistake, delete the Work folder and delete FarCore_a1.exe. After that all is well.