VPN access doesn't work wired but does wireless

Hello,

I am having a weird problem. Just installed a Belkin G wireless router - couple years old that I just inherited. Wired, I can hit the internet but when I try to access my work VPN wired, I can't. It never gets through the router - tech support at work confirmed I never reach the VPN.
So tech recommended I unplug and try wireless, which works! Went through Belkin settings and didn't see anything specifically related to VPN. The box says this router supports PPTP and IPSec pass-through.
What is preventing the wired connection to get through? I prefer to be wired if I'm at my desk as it is faster.
Thanks in advance for any ideas!