I've got a 2006 with the same problem. I'm planning to fix it next weekend. From what I've researched, for the most part, the gasket is the difference. A cheapo was used from 2005-2008 and it leaked whether your cases were perfect or not.
I also found that some people had a case mismatch, in which case it wouldn't matter which gasket you used, you would still have the problem. My plan is to remove the top end, then check the cases. If all is well, I'll put on the new base gasket, a new head gasket, new o-rings, and go back together. Worst case scenario, if the cases are mismatched, I'll make a decision on what to do. Most likely, I will grit my teeth, disassemble the bottom end, match the cases, then go back together.
Make sure to remind the shop to check the case halves, and let you know if they have any doubt about their condition. Splitting the cases will involve several more hours, and a bottom end gasket set, but as the old saying goes, "There's plenty of time to do it right the second time around."