Thanks! Next time this happened I was going to delete stuff piecemeal to identify the culprit. I'll start with that file first.

Try trashing your Skype preferences. See my other post here for the details.

Try trashing your Skype preferences. See one of my other posts here for the files.

Check the settings for Skype in Adium One option is "Auto-start Skype if not running"

I to encountered this problem. It was working fine for me, then stopped working during the process of trying to debug another problem.

I fixed it by closing Skype, then deleting ~/Library/Preferences/com.skype.skype.prefs, ~/Library/Application Support/Skype and ~/Library/Caches/com.skype.skype

Likely not everything needed to be deleted, though.