Do you mean it only plays for two minutes in a player? Does it play if you refresh the browser? What playback client are you using?
Please re-start Wowza. Start the stream in StreamManager (or /conf/StartUpStreams.xml ), then test playback in the Wowza Flash RTMP Player until you see it stop.
Then zip up the /conf folder and the current access log showing the above re-start and tests.
Is the IP camera accessible? If not, can you make it accessible with a public IP? Send that if so.