No bent pins. Asus tech support said RMA. Then, to make the story stranger, a friend dropped by after work, stuck a stick of ram in slot D1 (which never worked), and it booted and saw the ram stick. So she stuck them all in there and it now saw only the right side of the board. (Before it started giving error 53 it would see only the left side). Then she put them all in A1, B1, C1, and D1, which is the configuration I had it in the first time (when it would only see the left side of the board), and it suddenly saw all of the ram. All's well that ends well? Except it has a consistently bad SATA port, and stubbornly refuses to install SATA drivers, complaining "Device type not supported."
At least there's now a chance that it will work long enough for the RMA process.