crash in contact list

Hi there,
I get another crash when hitting m in my contact list. To me it looks
related to that crash I got rid of by deleting a lot of messages. Guess
I could delete another whole load of messages, but I'd rather have this
bug fixed. So, the exception seem to origin in the three-line method

find_docid:

  def find_docid id
    docids = term_docids(mkterm(:msgid,id))
    fail unless docids.size <= 1
    docids.first
  end

Does it happen due to docids.size being larger than 1 or could this
exception be raised by something else in there?

Alternatively, how can I find the message that causes this problem?

Regards,
Philipp

$ sup
[2011-11-25 13:15:19 +0100] ERROR: oh crap, an exception
----------------------------------------------------------------
I'm very sorry. It seems that an error occurred in Sup. Please
accept my sincere apologies. Please submit the contents of
/home/murks/.sup/exception-log.txt and a brief report of the
circumstances to http://masanjin.net/sup-bugs/ so that I might
address this problem. Thank you!