Hanging up VoIP call causes limited network connectivity
I've run into a very strange problem with pfSense. After hanging up a VoIP call, the network connection on my wired Windows 7 desktop completely drops. It shows limited connectivity, but neither repairing it, nor releasing/renewing the IP address will restore connectivity. A reboot of the desktop restores all functionality. I'm not sure what information is needed to troubleshoot this, but I'll try to provide what seems relevant. It may also be causing temporary disruption with wireless devices on the network. The pfSense box does not seem to be rebooting.
The pfSense box is an msi g31tm-p21, with a Pentium E5500 CPU, 2GB RAM, and a 500GB hard drive. It has an internal 100Mb NIC as the WAN interface and a cheap Linksys 10/100 network adapter as the LAN interface. The The Windows 7 PC is a Gigabyte P35-DS3L with a Q6600, 6GB RAM and Windows 7 Home x64. The VoIP service is provided by Vonage with a VDV23-VD single line VoIP adapter. I also have a DLink DIR-628 acting as a WAP and a Fast Ethernet switch. From my desktop, I typically have a Terminal Services Gateway remote connection to work.
My pfSense config is dead simple. I installed it, set up the LAN and WAN interfaces, and let it go. The only configuration I've done is to set up DHCP and change the default password.
I realize logs are desireable for troubleshooting, but I'm not familiar with BSD and am unsure which log to look at.
EDIT: pfSense versions 2.0.2 RELEASE amd64