Yes, some of the OCLV braze on tabs won't allow the FD to get low enough to the big chainring on a compact crank. You have 2 choices - either you can order a Trek specific tab from a dealer or you can file the hole longer on your existing one.

I did both - I ordered one - about $15 - and while waiting for it, I filed mine. It works perfectly. When the new one arrived, it essentially was a standard one that'd been filed. I gave it to a friend who needed one, otherwise I'd have been happy to send it to you. If you'd like to send me yours, I'd be happy to file it for you.

But first, check to see if you even need to do it - many OCLV frames are just fine. Good luck.

55/Rad