Extensions changed out of the blue

Hi

On one of my servers a number of extensions became non-sip extensions out of the blue. In other words, it did not show that they are sip ones anymore, no more password field either. Sip show peers also did not show them anymore - which makes sense I guess as they were no longer sip extensions.

Where would I start looking to see what happened? I have recreated them and all is fine again, but I would like to find out what caused this.

Thanks for any input

Just some more info - the ringroups that related to those extensions have gone blank as well. The only thing that makes those extensions a common group is custom contexts, which makes me thing the issue lies there somewhere?