I used a 16 GB card for the first time today and although I filmed continuously for 50 minutes, multiple clips were formed on my P2 card, each 00:12:22:12 in duration.
Why not one long clip, broken only when it spans two cards?
Everything is operating normally. The P2 Card uses the FAT32 file format, which is limited to 4GB files. So each of your files is no more than 4GB large, and "spanned" together.