I recently bought a WPC100 wireless adapter for my wifes gateway computer and installed the associated software.
By that I hope you mean just the drivers, and not any other software (i.e. a Client Utility or other control software) that might have come with it. If you did install anything other than the driver, uninstall it and use Windows to control the Wireless networking.
After that, standard troubleshooting procedure would include checking to see if there is a newer driver, and if so installing it. That is an Atheros AR5008 chipset based card, however Atheros unfortunately does not supply drivers directly to end-users, so you have to find them elsewhere: http://atheros.com/pt/AR5008Bulletins.htm
Linksys has version 18.104.22.168, however I found newer versions up to 22.214.171.124 from other sources: http://www.laptopvideo2go.com/forum/ind ... opic=14858
If the newer driver doesn't solve the problem (there is a chance it might, but I'm not hopeful), then I think the problem may be your power management settings. See the following post, where I detail how to disable or turn off any power management for the wireless network connection: viewtopic.php?p=1950#p1950
Another possibility is that the wireless network adapter is remaining off after resume. If that is the case, and the driver update or power management setting changes don't solve the problem, then you might try using the Atheros Client Utility, which is exactly the type of software I told you to uninstall in the first paragraph. <g> Trying it as a last resort might help, as it might be able to independently power on the card: http://drivers.softpedia.com/get/Other- ... 0125.shtml
Let me know if any of these suggestions help, or if you figure something else out to solve the problem, Scott.