theres a cap on video recording, someone posted a thread on it maybe a month ago, on my 64gig playbook its 10minutes for a 1080p video, i believe its only aroun 3-5 minutes on a 16gig playbook, which is kind of silly but thats RIM for ya.
1080p records @ 2MB/sec. recording size limit is around 32 minutes. (~4GB)
some people bumped into a software bug which would stop recording after a few minutes.
I know this seems pretty obvious, but if it's FAT32 wouldn't the maximum single-file size be 4 GB?
You'd be correct if it was FAT32 but it's not. The PlayBook uses the QNX native filesystem, and as far as I know its max file size is larger than anything a PlayBook could fit.