Software Update for Snow Leopard

I have a UTStarcom UM175 Air Card and I'm using it with an iMac which presently has Mac OS X version 10.5.8 as the operating system.  I'd like to update with the Snow Leopard software.  Has anyone tried that with this Air Card and if so, what has been your experience?  The Alltel download site doesn't show any software for OS X beyond version 10.5, but the System Requirements on the box that the Air Card came in, specifies Mac OS X 10.4 or higher.  So I'm wondering if it will work with Snow Leopard, but I hate to go ahead an install Snow Leopard and then find out that it won't work.