Is it regularly updated? Is it free? If not then I would suggest you switch to Zonealarm.
Having said that I found an updated version of Zonealarm some time ago kept crashing my computer so I went back to Version 5.5.094.000 and have had no problems since.
According to some on the forum the latest version of Zonealarm has now overcome those problems but I am sticking with the version I have at the moment.
If you don't want to try the latest version I can email you the version I have. Just let me know via the envelope.