Player freezes very often

[Qythyx]

I'm running Windows 7 x64 inside another Windows 7 x64 host. This mostly works fine except that my VM freezes quite often, usually within 5 minutes of starting it. BTW, I'm running Player 3.1.3 build-324285. When it freezes there are a few symptoms:

1. The vmware Player program is not responsive. When I mouse over it my mouse dissappears, I can't access the menus, and the windows does not redraw.
   
2. The vmware-vmx.exe process in the host is usually frozen with zero CPU usage, although I'm had at least 1 case when it was pegged at 100% usage. In that case the vmware Player program was responsive, but the VM in it was not responsive.
   
3. When this happens I'm not doing anything particularly interesting in the VM (or in the host). That is, I'm not doing anything that is IO intensive or CPU intensive, etc.
   

Does anyone have any suggestion how to fix this or how to diagnose it further?

Thanks.

[Tom2k8]

What are the memory sizes of the host and the problematic guest?

What antimalware software do you run on the host?

Do you have some other critical (system, non-business) software on the host?

Is the freeze a permanent solid one or does it unfreeze after a few minutes?

[Qythyx]

Host memory is 8GB, guest is 3GB, although I used to have it at 2GB and had the same problem.

Antimalware on host is only Microsoft Security Essentials.

On the host I have lots of software, what do you mean by "critical"?

The freeze was permanent, or at least 10 minutes or so before I gave up. During that time disk access and CPU were both minimal or zero from the vmware process.

[Tom2k8]

With "Critical" I mean software like defragment, backup, anti-virus or cleaning software.

[Qythyx]

In that case, no, I don't have any such critical software running.