Switch VC Reboot on Commit

Hi, 

We have a problem on our EX4200 VC, when we make any change on our switch (12.3R6.6) VC one of the members reboots. The changes we have done is only a user profile (ro to super-user) and add a ftp on the system  services hierarchy.

Normaly there is no reason for this behavior.  

Suggestions?

Thank you. 

EC