Tor's log lines to stdout don't flush in time for Vidalia to see them?
Erinn has a heisenbug where sometimes her TBB notices Tor's log line about openssl version, and sometimes it doesn't.
My theory is that there's still a gap between when Tor writes logs to stdout, and when Vidalia starts being able to handle log events.
For example: it looks like Tor's stdout logs don't flush at any particular time. So the sequence would be: Vidalia starts Tor, Tor starts with a temporary log to stdout, Vidalia connects over the control port and asks for log events, Vidalia starts ignoring Tor's stdout, Tor closes its temporary logs which flushes all the lines.
One way forward would be to try a Vidalia patch that continues listening to Tor's stdout after it otherwise would start ignoring it; and then see if we get duplicate lines as expected or if we see any new lines we otherwise would have missed. Bonus points if the Vidalia logs label lines as "S" or "E" (stdout or event) to tell which line was which. I'm putting this in the Vidalia component until we've tried this experiment.