Dell Power edge 1950 Memory problems

I have a power edge 1950 and I tried to increase the memory when I booted the system I get a "System Halted" message. I installed Dell 1 gig memory in slots 1-8 the error I get is that the Dims in 5 and 6 are mismatched and Dims 3-4 are also. I can not enter "setup" or anything else!! When I got the 1950 it only had 4-1 gig Dims installed and there were empty slots between them.

I see on the  Dell web site where the owners manuals are available but when I try to download them the ftp times out. I also have a 2950 and I installed 16gig in that one with no problems.

Can anyone help me. Thank You George