DUN - Limited Connectivity

I have searched and searched and everyone else having this issue is using
Wireless. I am connecting Vista to the Internet using a serial cable &
Globalstar 1600 handset with Dial Up Networking. I am able to get the laptop
to connect to the modem, dial out and connect but Vista says limited
connectivity and the repair feature doesn't work. The phone shows data is
being transmitted and received. Vista even shows me a valid globalstar IP
address but the web or email fails immediately.
Please HELP, Globalstar doesn't support Vista so I'm on my own. This is a
commercial fishing vessels that NEEDS email working for our weather updates.
Or I install Virtual PC and install XP but that seems like a lot of work for
email