I've noticed the behavior mostly on the CCleaner Forums were it sometimes won't load at all, and most annoying is when in the middle of posting something the connection goes kaput.
My thinking is that ZoneAlarm "may be the reason" because disabling it and using the Windows Firewall allows the CCleaner Forums and some other sites to load without problems.
If anyone else is having this issue it'd help to know for narrowing down if it is a ZoneAlarm bug, or just slow servers causing the problem.
I'm not sure if this is what you're describing but lately my internet connection seems to "disappear" for lack of a better word. I use NetZero and the computer will disconnect and there is no pop-up warning that "the connection has been lost" like there always was before. I've been wondering if it's ZoneAlarm. The other day there was an error in the Event Log that said something to the effect that ZoneAlarm tried to write info to its log that was "more than 8 times" the space allocated for it.
I haven't been able to figure out anything that could be causing the disconnect but it's happening less often now.
It hasn't happened to me for a couple of days now, however it is as you described it's as if the connection is lost. I've dealt with several flavors of it where it may only be a few sites that won't load, to a worse effect when nothing works including using integrated update managers in programs.
By the way I have ZoneAlarm on my two systems WinXP and Win98 and they've both had the problem using my previous ISP which was InterLink (Dial-Up) and now my new ISP which is Netscape (Dial-Up).
What's prompting my suspicion against ZoneAlarm is because the behavior happened on my old install of WinXP, and has returned with my fresh WinXP install.
Could be a coincidence but I cleared all the permissions in Zone Alarm so it could relearn my preferences and haven't had any problems since.