DV Info Net - Strange import problem with CS6

Not sure if this is the right category to post this, but I've been shooting with this kit for a while and never had this problem before... I recently shot a 90-min live production with a GH2 and 2 Canon Vixia HF-M-41s. The Vixias record in 1.9GB chunks, and the GH2 in 4GB chunks. I use MTS Merger to re-join the files into continuous 90-min video clips, then convert to Cineform AVI with Prospect HD. I'm still running a Q6600 with 8GB of RAM and a non-CUDA video card, so the Cineform intermediate helps a lot with performance. The Cineform AVIs from the GH2 and one of the Vixias import just fine into PPro CS6, but the other Vixia's footage only imports the first 35 seconds. If I open the problem file in Windows Media Player, it plays the full 90 minutes. If I bring in the MTS-merged file (before conversion to CF AVI) into Premiere, it comes in with the full 90 minutes. If I convert the individual MTS 1.9GB clips to CF AVIs, they come in at about 11 minutes each, for a total of the full 90 minutes. It's only the CF-converted MTS-merged file that comes in with only the first 35 seconds, even though it is approximately 60GB and plays in full in WMP.

The original MTS files don't appear to be corrupt, because they import into Premiere just fine, and the CF conversion doesn't appear to be flawed because the other cams converted just fine. I've tried re-merging, re-converting, and re-importing with different settings and get the same problem every time with the footage from this one cam. The "stage left" Vixia footage has no problems, but the "stage right" Vixia footage exhibits the "only-the-first-35-seconds-of-video" problem every time, no matter what I do differently. I don't expect anyone to have a solution to this very weird problem, but any suggestions will be greatly appreciated!