I've noticed that with tor 0.2.4.10-ish, Vidalia can accumulate a lot of "Path Empty" circuits after a while. According to my control port, these are ONEHOP_TUNNEL circuits that haven't yet connected to a guard. They seem to stick around for days unless I close them. I suppose this could be due to the circuit build timeout changes in legacy/trac#7341, or Roger's "let circuits last forever if you have none open" hack from legacy/trac#3443, or directory guards, or $RANDOM_GUESS. I'll poke at it with gdb next time I notice it.