You can get older versions of Comodo Firewall at filehippo.com. Be sure to export your existing ruleset first if you uninstall.
Updates are made to stay secure. You might as well disable Comodo Firewall iif you are going to roll back. Downgrading didn't work for me anyways.
I've had this issue since version 2.0 when I started using it. When I install Comodo, it goes fast, but then as the list of policies builds up, it takes longer to remember my actions. This gets extremely frustrating as there is no way to fix it.
I thought maybe it's something to do with 64-bit XP, but I guess not since this guy has the same issue on 32-bit XP.
I don't think it has anything to do with how good your computer is because I have dual core [at] 2.2, Nvidia 9800GTX, 500TB SATAII HDD, 4GB DDR2, etc, while I know other people with not as good hardware but they don't get this issue.
I have version 126.96.36.1998.
Windows XP x64 SP2
I run Firewall and Defense+ on safe mode