Vidalia has no clue why Tor crashed, and says that it crashed because of ""
See bug #2062 (moved). Tor is crashing (or dying, or asserting, or just not there), and Vidalia is saying,
Please report the following error message to the Tor developers at bugs.torproect.org: ""
So there are at least two problems here. One is that Vidalia doesn't know what happened, and isn't doing a good job of finding out. The other problem is that instead of saying "I couldn't tell why", it acts as if the empty string is an error message. Not good.