Log & Transfer Glitch with AVCHD

Hoping somebody else has insight into this sporadic Log & Transfer glitch:

I'm logging & transferring AVCHD files from a Panasonic HMC150 into the most recent version of FCP. Here's my workflow:

1) Copy AVCHD files (preserving everything in the PRIVATE folder down) from SDHC media to my external HDD

2) Log & Transfer, Load the PRIVATE folder from my external HDD. All clips display properly.

3) Add clips to my project, transcoding to Apple ProRes

The problem:

Every so often a clip has a little glitch in the file. The glitch is sporadic--can't find a pattern in where it appears--but it does appear consistently. It appears as a thin horizontal line of artifacting during playback of the source clips in preview mode. When transcoding these files, the log/transfer will STOP at the glitch consistently, leaving me with a partial clip. I cannot capture those glitched frames, forcing me to lose a few frames and start re-transcoding further along in the clip.

I would just attribute this to corrupt SDHC cards or source media, but the same clips/files transcode without error on my PC with Adobe Premiere. It's an awkward workaround and I'd rather get to the root of the problem in FCP.

Thanks in advance for any insight you can offer...