Browsing websites has been a problem with XP SP3, IE8 and ZoneAlarm 8.1 and 9.1.007.002 for the past 3 weeks. This seems to affect all HTTP(S) traffic - even Windows Live Mail trying to syncronise with HoTMaiL.
A website can end up just sitting there with the animated icon saying it is waiting for the site and only displays after hitting refresh a number of times or sometimes not at all or having to copy the URL and open a new browser by pasting the URL into "Start > Run".
I thought it was my internet connection, but a loan router from my ISP has the same problem and the many speed tests I tried look correct at around 6Mbps.
The same thing happens with Google Chrome on all PCs where IE8 is installed.
Everything worked when I uninstalled ZoneAlarm and used Windows Firewall instead, but the problem returned when I re-instlaled ZoneAlarm 9.1.007.002.
The only PCs that work are ones without ZoneAlarm or those with only IE7 instead of IE8.
I have not made any changes to the programs installed on these PCs except for the usual Windows Updates. It looks like ZoneAlarm is incompatible with the latest IE8 installation or updates on Windows XP.