Tom,
Sorry for the shortness. I was in a time bind when I posted that. If we change anything on an extension you get an asterisk recording stating an error has occurred. I was not sure if the password-master had anything to do with it or not but we have not changed anything else.
You can change anything except for any extension parameters.
It seems to only affect the voice mail as you can still make calls. Even if you change like the password on an extension, it affects all of the extensions.
On another subject, we use several trixboxes for routing of did numbers for pagers. These have been around for several years, but they have all been hacked in the last month and all setting trying to make outbound calls. Since these are inbound only, it is just annoying, but I think everyone should be aware this is happening more often and the enemy is pretty smart.
If you need more info on the voice mail, I will post some logs.