Until a few weeks ago, Zone Alarm typically caught about 99% of all spam sent to me, with few false positives. But a few weeks ago, Zone Alarm started letting through more than half of all spam. I haven't changed any settings and this is happening on both of my computers.

I had this problem back in 2008 and it went away, apparently on its own, after a few days, but this time it's not going away.

Does anyone have any ideas on what's causing this or how to fix it?

Here is my Zone Alarm set-up:
Windows XP
ZoneAlarm Extreme Security version:
TrueVector version:
Driver version:
Anti-virus engine version:
Anti-virus signature DAT file version:995073504
AntiSpam version:
ZoneAlarm ForceField
ZoneAlarm ForceField Spyware Scanner
ZoneAlarm ForceField Anti-Phishing Database
ZoneAlarm ForceField Spyware Sites Database 03.895