Vidalia Relay Bundle running with the exit relay box checked
The Vidalia Relay Bundle is supposed to be a non-exit relay, and it is, but the box checked on the Sharing page is Relay traffic for the Tor network (exit relay). The configuration file looks like this:
# This file was generated by Tor; if you edit it, comments will not be preserved
# The old torrc file was renamed to torrc.orig.1 or similar, and Tor will ignore it
ControlPort 9051
DirPort 9030
DirReqStatistics 0
ExitPolicy reject *:*
Log notice stdout
Nickname default
ORPort 443
RelayBandwidthBurst 10485760
RelayBandwidthRate 5242880
SocksListenAddress 127.0.0.1
... so it doesn't look like we're running an exit relay, it's just the wrong box that's checked on the Sharing page.