Frame rates displayed in the project window

I have 3 files for use in my project. The project frame rate is set to 23.976.
All 3 files display as having a frame rate of 23.976 with mediainfo and in virtualdub.
After being imported to the project window, Premiere Pro says one file has a frame rate of 23.976, one is 23.97 and one is 23.98.

The one at 23.976 is fine.
23.97 goes out of sync with the audio.
23.98 won't display more than 3 mins of footage in the time line, even though the clip is much longer.

Anyone got an idea what the problem could be?

I take it the second and third files don't have a native 23.976 frame rate then? Have you tried converting the frame rate before importing them into PP?

Some files appear to be shown at 23,98 even when they ARE in 23,976. It should be a kind of bug from premiere, I don't really know.
BUT
just go to the window where you set the frame rate of the file (can't remember the english name of this window as my premiere is french and I'm not at my home right now),
then enter: 23,976 fps.
Maybe it will go back to 23,98 when you click enter, BUT it should be fine once you watch the file. No more "interlacing" problem due to the fact Premiere played the file at 23,98 instead of 23,976.

Cheers for the responses fellas. I did a quick test with virtualdub and converted a small portion of the m2ts file that I'm having problems with. This time I told it to convert the fram rate to 23.976. Don't know why it would make a difference since that's what it says it is anyway. The resulting clip shows the required frame rate in Premiere, so I'm converting the whole clip using this method. I binned the original 240gb file I had. Hopefully this time all will be well.