I hope you find a more elegant solution than what I had to do when I had a Panasonic HMC-150 which also has multiple 2GB files. I needed to go a windows command prompt and do a binary copy, like this:
copy file1 + file2 + file3 combinedfile
This takes some time to complete, but did create a concatenated file of all contiguous clips. But you need to identify which clips are contiguous. Total PITA. Good luck!
-Jim.