R310 Ram Upgrade

Hi there. My R310 has an x3440 xeon and 8gb 2x4gb Udimm ram, I just pulled 4x 4gb 2Rx4 Hynix 10600R modules from a known working R510, installed them into the R310 and it wont post, with all 4 sticks in I get 1and 4 on the status and with just 1 stick I get just error 1 on the front status. I know all 4 sticks work so its not the ram and the manual says it will take 2Rx4 1333 4gb sticks, so where am I going wrong?? I upgraded the bios to the latest version this morning incase it was that but also didn't help and I also tried 2Rx4 8gb sticks which also didn't make a difference. Anyone have any advice on where I go next?