Which bug? If you have one INI file per channel with only one section, it's not so great..
To avoid getting the one marked as deleted, it's pretty easy, just mark them with something super strange which is unlikely to be a quote, (like $+($chr(1),$chr(2),$chr(3)) ), and when you find a quote, check that it's different from that, if it's equal, just try another quote, pseudo code:

while ($findquote == $deletedmark) noop
echo -a quote: $v1

Looking for a good help channel about mIRC? Check #mircscripting @ irc.swiftirc.net