I have this same problem on a CentOS 5.4 X64 server. FOP2 dies randomly. I have tried what you suggested and these are the last lines of output.log:
127.0.0.1 <- Event: RTCPSent
127.0.0.1 <- Privilege: reporting,all
127.0.0.1 <- To: 192.168.11.129:19435
127.0.0.1 <- OurSSRC: 1859564915
127.0.0.1 <- SentNTP: 1260993389.2531479552
127.0.0.1 <- SentRTP: 1552160
127.0.0.1 <- SentPackets: 9701
127.0.0.1 <- SentOctets: 1552160
127.0.0.1 <- ReportBlock:
127.0.0.1 <- FractionLost: 0
127.0.0.1 <- CumulativeLoss: 0
127.0.0.1 <- IAJitter: 0.0004
127.0.0.1 <- TheirLastSR: 0
127.
The complete log is 126mb because today it lasted over 8 hours without crashing. Some days it can crash every few hours.