UM175 won't give me internet after the first time

[DCH]

I have an IBM Thinkpad and the UM175 modem.  The first time I connect, things are ok (although connect speed seems slow).  If I disconnect and reconnect, then even though it says I am connected, I have no internet.  Even when it tries to pull up the usage I get site not found.  I know it isn't just a DNS issue because I can't even pull up sites I know work with just the IP address.

If I reboot the computer, I get one shot at connection...once I disconnect, I have to reboot to get a usable connection.  Most of the time, after disconnecting the first time and trying to reconnect, I get "A connection to the remote computer could not be established".

I have uninstalled and reinstalled the VZAccess manager to no avail.  I suspended the antivirus--no difference.  I went to a Verizon store and talked to phone tech support...they didn't have any ideas.

Anyone here have something I can try?