After Firefox updated today, CF3 stopped recognizing it after restart, no matter how many times I set it as a “Trusted” app. I looked in “Network Security Policy” and (unsurprisingly) it was littered with SHORT PATH rules (i.e., D:\PROGRA~1\Mozilla Firefox\firefox.exe) for each time FF tried to connect—the same thing that happened with Mailwasher and described in detail in this post. Only by clearing the rules and restarting the machine (restarting either CF3 or FF wasn’t enough) did CF3 play nice with FF, managing to define a rule with a FULL PATH (D:\Program Files\Mozilla Firefox\firefox.exe).
Because of this, and the fact that Defense+ is not really working in my machine, I decided it was best for me to go back to CF ver.2.4.28.184… at least until a version comes out that can work in my machine.
(:SAD)
This is a known problem. If you want to try a work-around, you can just delete all the Firefox entries in Network Security Policy (including the one that used to work) and reboot. When you next run Firefox, you will be given a pop-up “Allow” dialog. Select the “Treat this application as…” and choose Browser from the drop-down. Worked for me…
Yeah, and that worked for me too, but I want to avoid having to reboot when that happens 
Also, I kind of wondered if it was really worth it keeping it installed when only the firewall part was functional in my primary PC. At least I know CF2.4 does work there. I wish I could find what’s causing CF3 to misbehave in that particular machine, but I’ll just wait until the next version. One less thing to worry about. Besides, that will help me to stop whining about it in the forum; I’m not helping anyone with that.
CF3 is installed in my secondary PC, and both the firewall and Defense+ are working very well there, as far as I can tell. 
The developers are hard at work on fixes and I understand that a newer release will be out shortly. It’s a huge piece of code, so there are going to be a few wrinkles to iron out.
There is a similar problem with AVG anti virus program. I think the devvers are aware of the problem. Just wait for the first updated version that should be here any time soon.
Waiting is no problem :). I’ll keep visiting the site periodically to check how things are going. You can be sure I’ll start downloading it the second I see it posted ;D