I just experienced a weird problem with a VPN client tunnel on a 32bit Windows Vista box. We are not able to reproduce the problem on XP.
Cisco VPN client v5
Windows Vista 23bit
Internal Group w/ RADIUS
I had a home user who was teleworking and when they would connect to the VPN with Vista they were reporting that ipconfig/all was showing no DNS and they couldnt ping anything using the FQDN.
Exporting the PCF file to a XP machine and the same problem would not happen.
The tunnel is a split tunnel, and I did read the section in the release notes "DNS Server on Private Network with Split DNS Causes Problems". We do not have the ISP's DNS servers in our network list. However for kicks I removed Split DNS Names just to see what would happen. It didnt fix the problem.
The only way I was able to correct the issue on Vista was to remove split tunneling alltogether. Which isnt really my desired result.