Thanks Allan Eckert!
First Googled the error reference and nothing relevant found.
Googled Apple Hardware Test memory error and found this interesting thread:
http://hintsforums.macworld.com/showthread.php?t=104223
DeltaMac -
The hardware test is showing a 'mem' failure code, or a memory failure. It doesn't necessarily mean that you have a bad memory chip. Try removing and firmly reseating both of your memory sticks (swap the memory chips between the slots as another good step), then run the hardware test again.
If you get a failure code again, try removing just one chip at a time, and run the test again. You should be able to find just one chip to blame.
It's also likely that reseating both chips the first time may clear that test code completely.