See: this question Same problem here, but not using FF but IE6. Buttons in client don't seem to work, could this be related? EXTERNALINTERFACE: Session failover from XASInstance: {503baf88-db13-4bb3-94b3-e5d372d52dde}; number of failovers for this session is now 2 I'm aware that this is the same question as: this one. But couldn't figure out how to 'kick' the other question to the top of the pile..