Steam works perfectly fine with FX based processors. Are you certain all of your spare parts that have been cobbled together are all in working order, or configured correctly?
There was one issue of interaction between Steam and FX based processors that I am aware of, but that was patched out shortly after the FX line of chips launched. It was rectified by updating the BIOS of affected computers. You should check online for your make/ model of motherboard and see if an updated BIOS is available. From my understanding, the conflict was actually Steam's fault, in that it used a particular feature of the processor for their DRM in some titles, and the FX simply handles the usage differently, but not incorrectly, from how Steam expects, hence an inability to verify and start a game running correctly. I'm a bit hazy on the specifics, sorry for the bad explanation.
Most likely, it's your BIOS, as the date on it of, 11/30/11, is just shortly after the FX line was released. It likely doesn't contain the update that addressed Steam's issue.