Wireless Advance Button Greyed Out!

I work in the pharmaceutical industry in the IT department. I currently
support just shy of 400 users. At least half of the users use high
speed to connect to our network and most of them use wireless. We
currently use Toshiba Tecra M3 as a standard for their laptops. When we
set their laptops up here, we are able to connect to our wireless
network here which is a Nexland router. As soon as we send that laptop
out to the rep and they try connecting to a different wireless network,
usually they will be able to connect up just fine only ONCE. After
that, they try right clicking on the wireless network connection, and
click View Available Wireless Networks. Once that window comes up,
everything is greyed out EXCEPT the cancel button. In this case we are
forced to have them run a script that reinstalls their wireless network
adapter from an unzipped file from Toshiba that includes wireless
network adapter drivers and then the user has to reboot in order to be
able to connect to their network. Is there some kind of fix or
something else we can do to NOT have to reinstall their wireless
whenever they wish to connect to a different router or network?