Hey guys,
A while back, I tried looking into getting WikiPBX to work with mod_voicemail and gave up because there was some fairly big "missing links". It was related to the difference in multi-tenancy approach, the standard way vs the way that WikiPBX does it, as described here
If I remember correctly, freeswitch was making some directory requests to WikiPBX only passing in the domain and no sip profile, which WikiPBX did not know how to answer. Then things would go downhill from there.
I guess the best approach is just to take a fresh look. Try to make mod_voicemail work on a freeswitch installation that is running with WikiPBX, and then when things break, paste the output from the WikiPBX console and we will look at it and try to figure out how to get around the problems. If there is no output then you can add some logging statements or we can check in a change to svn to spit out more debug.
I'd really like to get WikiPBX working with mod_voicemail too. The built-in voicemail with WikiPBX is limited in that it cannot do MWI (message waiting indicator) notifications. So until that happens, it's not a workable option for many people.
HTH,
Traun