I do a lot of mobile wifi over public networks, so have the same problem with all the firewalls. They want to help you set your trusted network up so you can do sharing, incuding SSDP (is that what you mean by discoverable, port 1900?-if you mean on the internet with GRC tests, that is usually your router), and I have to go in and kill it all. I have a network, but none of the other computers are known to me and I don't trust them or want to share with them. If you uncheck the "trust" on the Network popup in OA, it does the really serious stuff, but doesn't block everything some might want. BTW, I got them to add the "trust" box as a beta tester.

As far as the unsigned drivers, they are still all over the place with Vista x32, and you just need to see if they are for something you recognize and allow them, or deny them and see what breaks. Supposedly x64 changes all that, but I don't use it. The new OA release is the result of another 4.5 months of beta testing, including public beta releases, so is of a caliber with the Avast! new releases. I currently have no open bug reports with it, but they tried to add something in 3.1.0.27 that didn't work right under Vista and are now deciding whether to remove it or fix it before the release. So something to keep an eye on in the nearer term too if you decide you need more protection.