Seems the file size limit is 2 GB. Only way around it I can figure out is to record channels 1&2 each as mono rather than a stereo pair, effectively doubling the length I can record on 2 channels. I just got DP 5 running, and it seems this is the approach it automatically takes when recording a stereo pair, creating a left file and a right file.
Who wants to record something less than 2 hours and 4 minutes? That's when the music is just getting good!