A bit of necromancy perhaps, but I seem to have a similar problem now. I updated my contacts plugin to 0.7 and now I can't access settings for my IM/VoIP accounts. Neither can I add any new. Clicking the VoIP/IM accounts in settings simply does nothing.

Already configured accounts are working properly. So its just the settings screen that refuse to launch.

Things tested:
*Install even later version (0.8 from... was it in testing?)
This produced no change in behaviour at all.

*Uninstall all conversation plugins (Except Pidgin extra Protocols Sametime and Bonjour, as these refuse to uninstall due to other dependencies, despite everything else I can find that should be related is removed).
With all these removed I can again access my IM/VoIP settings. But, I can't use MSN for instance of course since the support it now gone...

*Reinstall Extra protocol plugins for Conversation and Contacts 0.8.
This immediatley reactivates my MSN-account (The settings are saved even through uninstall. Guess I would have to purge to remove these?) and also reintroduces the problem where I can't access the IM/VoIP settings.

Any clues people? Next on my todo list is try and uninstall and reinstall an earlier version (0.6 then I suppose?) and se if that will at least let me modify my accounts. Will be happy for any suggestions on how to proceed beside using an older version (if even that works).


---SOLVED---
Seems libpurple caused some conflicts in the background. Couldn't find it listed in App-Manager, but since that bonjour package gave listed a dependency to something with version 2.6.3 i ran dpkg -l | grep 2.6.3 and that showed me some libpurple packages. Removed those with apt-get remove (was one for the bonjour, sametime thing. And one more "libpurple0" for the actual lib itself).

Then I fetched and installed "Extra protocol plugins for Conversations and Contacts 0.8" through App Manager again, and now all seems to work as expected. It did give me some grief with my MSN(Haze) account. It was still listed, but unable to connect. Closer inspection showed it had lost the username, so I had to remove the account and add it again, since the phone won't let me edit the username field. Thankfully it then connected properly and it had no ill effects on my many merged contacts.

Perhaps this wall of text can be helpful to someone...