I sometimes have some problems.
I plug the SDHC card on the mac, and FCP (with L & T) doesn’t recognize the file structure (even when i didn’t modify it…).
I erase totally the SDHC card, put it in the cam (HF S10) and copy the files again, and when i plug the card back to the mac, i can find them in Log & Transfer…
Hope this works for you,
KIdd