Windows 7 & CA Firewall Help

After trying "everything", I finally got MediaShare to work on my HR21/700 by disabling my CA Firewall, and doing a "red button reset". I was able to view some photos, and play some music. Then I decided I better turn the firewall back on, and sure enough, the song stopped playing. I tried this cycle over and over again with the same results...disable firewall, next song starts playing...enable firewall, song stops playing.

Am I to understand that in order for MediaShare to work properly I need to keep the firewall disabled? Isn't that risky?

Is there any way to keep the firewall enabled and have MediaShare function correctly? The CA firewall is completely configurable, but I have no idea if opening a certain port (or some other adjustment) will fix this issue. Certainly, CA tech suport know nothing about the HR21, so I really hope someone here can help me.

If this is a "known issue", and perhaps there is a fix using Windows Firewall, I can turn off the CA firewall and use Windows firewall.

PLEASE HELP!