GlobeTrotter Connect failure with Mac OS X 10.5.5

I bought an AT & T USBCONNECT Quicksilver Data Card to use with the late 2008 MacBook Pro. The laptop has two partitions, one running Vista, the other Mac OS X 10.5.5 (forget version number, but whatever came with the laptop).The Data card works flawlessly with Vista with the drivers provided both with 3G and EVDO. However, when booted under Macintosh, the GlobalConnect software cannot find the card-get message that "No card found". I know the card works,
and the USB port works because it is fully operational under Vista, but I need it to work with Macintosh.System Profiler sees the card, also. Have uninstalled/reinstalled/restarted multiple times. In the Network prefpane, there are two items listed under GlobeTrotter Connect version 1.3 (Option 3G Ethernet and Option 3G Modem); for both, it states that"Cable unplugged." Does anybody have any idea how to make this card work with 10.5.5 (the software states it's good for 10.5+)? AT&T refuses to support MacOS, period.Option, the company that makes the software probably won't help, as this is not their card, but I requested support anyway.Any help appreciated, otherwise I will have to return the card. BTW, it works great with Vista on the same laptop 🙂