The logic board will not sit soundly into the midframe

I am currently trying to reassemble my current iPhone 4 CDMA model and the logic board is just not going in. It is inserted into the little notch at the top, but will not sit down into the mid-frame of the iPhone unless I am holding it down with my finger. I read that if the logic board is not sitting soundly without you holding it down, you need to do it all over again. Any tips on how to accomplish this?