Help adding NTSC file to TMPGEnc DVD Author

[Doobie]

I'm trying to add a NTSC VOB file to TMPGEnc DVD Author. The video is about 44 minutes long (1.6GB), but TMPGEnc reports the file as 0min01sec (several frames in length). This problem exists even when the file is split into m2v/ac3 files. But, if I chop the length in half, the file adds correctly to TMPGEnc, just without the portion cut off.

Any ideas? Thanks in advance.