I've seen several articles about this issue, but none that have solved my problem: I can connect my Mac OS or Windows Guest OS to the internet using my AT&T mobile broadband card, but not both at the same time. I'm guessing the solution may be to upgrade to Parallels Desktop for Mac 3.x and enable "Shared Networking" (an option that is grayed out in v2.5), but want to confirm there's not some simpler/cheaper solution. The Problem I can connect the Mac OS to the internet using the GT Ultra Express PC card and GlobeTrotter Connect software, but the connection isn't shared with the Windows Guest OS. Alternately, I can connect the Windows Guest OS to the internet using the broadband card, but only if I uninstall the GlobeTrotter Connect software from the Mac---and of course I can't share the Windows internet connection back to the Mac OS. Environment - MacBook Pro running OS 10.4.11 - Parallels Desktop for Mac v 2.5, Build 3214 - AT&T GT Ultra Express PC Card Is upgrading to PDfM 3.x the only solution? Is it a guaranteed fix?