Firefox/Hibernate issue

Since installing Comodo a week or so back (to replace Vista firewall) I have had a problem on my notebook with Hibernate mode if Firefox is running. The PC will hibernate correctly and will come out of hibernation correctly - but Firefox will not connect to the net any more. Other applications that access the net (e.g. Gmail Notifier) are fine, and I did not have this problem before installing Comodo, hence posting here. I have to close Firefox and restart it when I come out of hibernation before it will work again,

Any clues?