Here are the relevant quotes from that Topic:
Yes, I'm with you, it's incredibly annoying. I've also asked if we could have it bumped to 2.5 hours. The trouble is that the .mp4 format requires some kind of table thats stored in ram. it's apparantly a big table that maxes out the 4MB of RAM on the system at 2 hours. Apparantly it could be fixed by using another recording format, but then that wouldn't play on the PSP or iPod. Unfortunately, those are the options we have with the R2 hardware right now.
From what I have been told, the only software fix is to use a different file wrapper (ie. avi or asf). Let me get with the folks here to see what we can do about some kind of exchange or upgrade type program...
So I am just going by what I have read.
I agree it is a serious shortcoming.