Strange AOS cluster...

Hello, we have 3 AOS, sharing one appl. directory setup as a (axapat not Win) cluster. User A connects to AOS1 and runs a programm, the programm crashed with some method error. User A connects to AOS2 and the program works fine. User B connects to AOS1 and the programm works fine. User B connects to AOS2 and the programm works fine. User C gets errors on AOS1 and AOS2… Funny isn’t it? We stopped AOS and AOS server manager, but no difference! Guess the only (quick and dirty) will be to reboot the 3 AOS and hope … Did anyone have the same problem? Is anyone also haveing AOS clusterd? THX Pirmin