Multiple printer issues using Bonjour

Hey guys,

I have a problem with my printers using bonjour for windows. Here's my setup:

2010 iMac i5, Parallels for Desktop, Windows 7 64 bit installed on parallels, Airport Extreme, 2 usb printers hooked up to airport via usb port on the airport, one network printer. Ok first of all, all 3 of my printers work fine on the Mac side. I setup the bonjour for all 3 printers, and they are active. However sometimes when I go to print the settings will be grayed out and won't allow me to print. But sometimes it does. My default printer in the Parallels for printer port 1 is set to one of my usb printers. Why does it grey out sometimes and at other times it allows me to print and change settings? I need to be able to access all the printers. I also tried using setting up multiple printer ports in parallels and assign them to the ports, but they don't show up.