What gets me is this "Invalid or unsupported form of compression" error, which I have never come across in relation to the web shield in all the time that the web shield has been incorporated in avast. It makes me wonder if you aren't using some form of encryption program, proxy, or web acceleration application ?
Personally I would never go back to AVG after 6 years away (so 4.8 is the better of the two options) and even longer away from ZA, which I feel has become bloated and not as good as it once was, the free version being restricted in the hope you will buy the Pro version.
Many forum users are using these:
- PC Tools Firewall seems to have the least user headaches as it doesn't seem to be constantly asking the user questions about this and that.
- Online Armor for the most parts fine but it has caused some users grief after avast program updates and that is something you have to watch out for.
- Comodo is now a suite and you have to do a custom install so as not to install the antivirus element (or use the add remove programs to remove the AV element if already installed), of all the firewalls listed this seems to be the noisiest in asking questions, depending on settings and elements used (Defense+), so it could be daunting for those not to familiar with firewalls or their systems.
- Outpost Firewall 2009 free, a cut down version of the Outpost Firewall Pro version, which should still provide good protection, http://free.agnitum.com/
. Download, http://www.filehippo.com/download_outpost_firewall/
There is a new pre-release version 5.0.394, http://forum.avast.com/index.php?topic=54491.0
which should be out soon and that seems to have resolved the major issues with 5.0.377. However, as I have said I have never seen what you are experiencing here "Invalid or unsupported form of compression" with either 4.8 or 5.0 so I don't know if this would make any difference.