Hi,
After installing the latest update, a message popped up and notified me that the update will take affect only after a reboot. I could choose if I want to reboot now or reboot later. So far so good.
But, when I chose later - it seems like the firewall froze and closed itself.
Afterwards, I had to reboot immidietly to prevent any security risks, and everything was fine.
Thanks.
OK. Here’s the extra info:
Let me know if you need any extra info. 
Thanks.
I also wonder, did you upgrade from CFP 3 or the earlier CIS?
LA
Not sure what’s the difference.
I was using Comodo Firewall 3.5.X
I see. I asked because there were two options: either you had CF 3.5.53896.424 (from the CIS installer) released 2008-10-23, or you had CFP 3.0.25.378 released 2008-05-30. In the first case, updating should be fine, in the second case, update wouldn’t work. If the first case apply to you, I guess you’ve encountered some kind of bug. If you can’t get it to work, I suppose a fresh installation of CF from CIS 3.5.54375.427 would be a solution.
I hope I didn’t confuse you.
LA
Ok. Now I’m even more confused. 
If CIS was released a week ago then I had the CFP version.
I searched for the installation file, and found it to be ‘CFP_Setup_3.0.25.378_XP_Vista_x32.exe’.
So apparently, the update was not suppose to work.
But now, when I go to Misc —> About and look at the version number, it’s seems to be:
3.5.54375.427
OK, sorry about that.
If you actually have 3.5.54375.427 now, you do have the latest, and it should also be labeled as “Comodo Firewall” instead of “Comodo Firewall Pro”.
LA
Too late.
Already re-installed :-/
Oh well…