Comodo Locks up Dell Printer in 3.5,3.8,3.9,3.10 CIS versions.

I've got a Dell 948 All-In-One Printer, and I had the same problem: printer worked when the Firewall was turned off, but when it was on, it would get to 10-20% complete in the taskbar popup window, and it would just freeze without printing anything, and I'd have to click Cancel Printing to unfreeze it. Sometimes I'd get a balloon telling me there was a printer error, sometimes not.

I'd designated the dell apps and the spooler as trusted in CIS, even un/reinstalled the printer drivers, tried a different cable, nothing worked.

And then I when I checked out CIS > Firewall > Common Tasks > View Firewall Events, I noticed that a bunch of system and spooler UDP and TCP events had been blocked.

So I went to CIS > Firewall > Advanced > Network Security Policy > Application Rules. The first item in the list was "Windows System Applications" and the policy was set to "Block All." The trusted apps were there, as I'd set them, but they were listed below in the rules llist, so the Firewall would encounter the first rule, block access, and stop there, as it should.

Usually I put in a rule like that anyways, since I don't like MS communicating when I don't know about it, but this would actually be a bug in my case, since the rule in the top order was applied from a fresh OS install. All I did was move that rule to the bottom of the list, which allowed the trusted apps rules to be first on the list, and the printer worked.