Dell e521 0UW457 CPU x2 5200 65nm upgrade?

Okay I want to know if there is a full list cpu compatibility list for the mobo. If not I would like to know if any one has got the amd athlon x2 5200+ 2.7 65W to work and if so how. I have tried extensively to get it to work myself. I have Bios rev 1.1.11. I have cleared cmos to see if that would work. But I just have a hunch this cpu will work. Does anyone Have their two cents to throw in, maybe I'm forgetting something. Any help will be most appreciated.

Hi Kre110:   The 5200+ will work just fine in the E521, I'm using one right now.  I also run one in a C521 slimline, no problems.  If I'm not mistaken you can go to the 5800+  65W.   I haven't looked into if the higher watt chips yet so I don't know about those. 

Good Luck