Do you see anything in your log statements that may provide a clue about this behavior? Please provide some additional detail about the problem including the platform, operating system and Java version on which Wowza Media Server is running. Also, tell us what player client technology is being used (Adobe Flash, Microsoft Silverlight, Apple iOS device, Set-top box, etc.). If a live workflow, please share what live encoder/IP camera manufacturer/version and exact encoding settings that you re using.
You may also zip a copy of your [install-dir]/conf and /logs folders as a .zip file (or other archive) and send them with a request for help to email@example.com so we can take a closer look at your configuration and server activity.