Stable with the A-DATA Dimm's in 1 and 2!
Now here's the thing? after reviewing the manual, it shows 3 combinations of how to use the Dual chanel function and says check the table below to see the 3 combinations, until today I had never found this table as it's not below the text but actually on the page above! until today I'd assumed it was the same as my Asus A8N Sli prem board! certainly the Dimm slots are colour coded the same Green 1 and 3 - Purple 2 and 4.... turns out the Dual chanel config is 1 and 2 - 3 and 4 or 1,2,3,4 but with the matching sticks obviously in the pairs 1,2 and 3,4!
As I was running A-Data 1 and Geil2 - A-Data 3 and Geil4 I think the board was trying to run Dual chanel with mismatched sticks! and certainly with the CAS latency prob this was never gonna work.
I'm gonna put the Geils into 3 and 4 now and see if it's still stable with all 4 Dimm's back in - Fingers crossed.