The chat room uses application variables to store the real time data for the chat room.
Applications variables are stored in the application pool process for your website. If the application pool process is being recycled, dropped, or you are using multiple process then you will get the problem that you are having.
You need to check the following with your forums website app pool:-
- Use only a single worker process
- Disable rapid fail protection
- Recycle only once per day at a quite time like 4am
- Use a separate application pool for the forum to the rest of your website incase another application is crashing the app pool
- Monitor the app pools process ID on the server. If it changes then something is causing the app pool to recycle or crash