I had a few cd´s copied with expanded drum tracks, and they sound awesome. There is just one problem.

When I import them into Logic Express 7 (mac), I have to set the tempo for them, but not to the exact tempo. Like if I import one that is at 100 bpm, I have to raise or lower it slightly... sometimes up to 1 or 2 bmp.
If I dont, it will make a weird little click at the end of each imported file, and come up saying that there was an error and it was returned to the core audio file.
Now the real problem is that the time changes slightly throughout the song. And then if I try and change the tempo, it will start moving everyhting around...
Could it be something to with the energizer the programme has? I have used it once to speed up a tune.. could it be that it is still using it?
It is really annoying, since it takes forever to contsruct a drum track that is in perfect time (especially without the help of a click.).
Is there a way of making the arrange window not work with click... seconds or something?

Any help would be great! I am as confused as Jesus on a PogoStick