2007 Galant AC is out, again

ast summer my girlfriends Galant started throwing a code which I cannot remember, the green AC light blinks. She went by a local shop who evac/recharged last Friday, and it's leaked out already. One of the older Mitsubishi forums mentioned last year this is a known issue with the 2007, I believe they mentioned the upper evaporator?

This car has been nothing but junk, had to replace the AT with less than 90K miles, it's just been one thing after another. I called Mitsubishi America, spoke with a customer service rep who was kind enough to say even though the mileage warranty was up, she had the remainder of the 3 year which expired Jan/1/11 and they could possibly work something out as they value our business. I went to the dealership, 50 miles away, who tried to charge me $150 to evaluate the code/car, and pretty much tried to scare tactic me into believing Mistubishi would never warranty the car and it was a lost cause. I was frustrated driving 100 miles for nothing, I left, and of course the warranty is out now. I feel bad for my girl as she still owes $5k on a piece of junk.

End of rant, bottom line, what could possibly be wrong with this AC, what questions should I ask a shop, and what should I suggest they be on the look for? It's been sweltering hot, no way she can make it all summer with a 7 year old in tow.