UPDATE... Update...
When I noticed that Muggles was running an older version of ZAP (ver. 2.6.357) than I am (4.5.554), I got brave and tried updating to avast 4.7.871. I shut down my copy of ZAP and closed all other operating programs -- as I always do when updating or installing new software. Then manually updated avast. Avast 4.7.871 is running fine on my Win98 SE machine. I rebooted the PC as instructed, and avast icon is on the tray as is the ZAP icon. This version of avast did not break my internet connection (DSL) . As expected, I did have to tell my ZAP firewall to allow avast to access the internet. I have the same 3 modules of avast running as I had before the update to .871.... 'Internet Mail'; 'Standard Shield' and 'Web Shield'. I don't use P2P, IM or Outlook, so those three are grayed out.
Muggles, maybe you could upgrade your ZAP to the same version I'm using.... 4.5.554. There's a link posted above if your interested. Just a thought.
Hope this helps.