Having problems with FX 3.5 and FW.

I run Comodo 2.4 on one image of Win XP (with a separate HIPS). I just upgraded this image with FX 3.5 (I still have the FX 3 image so I can revert back to it if I can't solve this). In the app monitor of CPF 2.4 I have FX.exe allowed thru tcp 80, DNS 53 to my router, and also 127.0.0.1 (which has worked fine with all the previous FX versions since FX 1... series), and have deleted the FX.exe application rules and reinstalled the same rules after I initially upgraded FX 3 to 3.5 (and also after the new install), and when these connection problems appeared, I uninstalled the upgrade, cleaned out all the leftovers from all the user/admin app data/local settings accounts, the program files left-over Mozilla folder, and then cleaned the registry, before installing FX 3.5 as a new install instead of an upgrade.​

FX 3.5 works fine for about 5 to 10 min. then the logs indicate that the application monitor is blocking Fx 3.5 out to tcp 80 as well as the DNS (even though the rules are "allow"). I don't know what's changed in FX 3.5 but it initially appears to be a problem with the FX 3.5 cache, at least something has changed in the way the FX 3.5 cache works in relation to the way it worked in 3.0.​

Also 3.5 is not renewing the XPC.mfl and XUL.mfl files if these are deleted, the way FX 3.0 did. After a log-off/log-on back in the user/surfing account or a shut-down restart, FX 3.5 functions as normal for a while. The only thing I haven't tried that I can think of is reinstalling CPF 2.4 as I have the network rules backed up. Just wondered if anyone knew of if/or what has changed from FX 3 to 3.5 to cause a delayed connection problem with the SW FW rules. thx.​