Posting on behalf of Foxie
Some main players and just about every sandbox player must be aware of the sui bug by now: Someone suicides from a game and votes break, forcing anyone who hasn't voted (which tends to be the majority) to veg.
I hosted a large setup a few days ago wherein over a dozen players ended up suiciding over the span of 10 days, but the game never broke. This setup was nothing but blues and nilla mafia.
So I suspect this bug is related to certain roles, not completely arbitrary as we thought. This can mean it happens when some roles suicide, when someone suicides in the presence of another role, when a specific role suicides in the presence of another role, etc.
If you'd like to help figure out what these exact circumstances are so that a few years from now when lucid stops by he can fix them, post any games you've played that were broken by the sui bug here (or PM them to Foxie if you can't post).