WLM2009 hangs

Hello:

I used to have WLM8.5 installed on my Lenovo W500 laptop Windows XP and
worked fine. Now it forced to upgrade to WLM2009 and problem starts. After
signed in for a while, WLM freeze. WLM process take about 56% CPU usage and
I can hear some sound like "ssssssssssss", most likely from HDD, but HDD has
no problem at all. I suspect that Macfee firewall/Antivirus software may
cause the problem. However I am not able to disable firewall/antivirus to
test my thought as it is company laptop. I am just wondering why 8.5 works
fine but not 2009. I hope to have some tool or idea to check what is the
actual problem e.g. WLM2009 use some new ports compared to 8.5.

Any suggestion? thanks