Update:
I uninstalled 7.0.59, installed 7.0.58, same issue
Then I tried Driver sweeper, removed all the NVidia hidden files and reg entries, booted, did a fresh install of 7.0.58 and sam thing and this in the log:
3/31/2013 1:40:22 AM | World Community Grid | Starting task X0930126750857201105260942_1 using hcc1 version 705 (ati_hcc1) in slot 8
3/31/2013 1:40:23 AM | World Community Grid | Computation for task X0930126750857201105260942_1 finished
3/31/2013 1:40:23 AM | World Community Grid | Output file X0930126750857201105260942_1_0 for task X0930126750857201105260942_1 absent

They are starting and going to computational error in the same second..
Well I've been wanting to replace this board with a Intel Z77 board I have and I guess this is the motivation to do so..