HTC 8125 / 8100 / MDA (USA) / K-JAM / P4300 (Wizard)

Is there a good anti-virus program that works well on this phone (preferably with a free trial period)? I tried to download an F-Secure trial version and it crippled my phone to the point where I could not send or receive calls (or find a network to connect to). I had to uninstall the anti-virus software to get my phone working again.

Thanks