So this is a new problem I ran into with the latest laptops from Apple, but it isn't Apple's fault.
I narrowed it down to HP's sh*tty drivers for the LaserJet 3600. If I try to print over wireless from the latest Apple laptops (unibody aluminum or plastic MacBook or MacBook Pro), the print job will completely kill the printer; no one else will be able to print to the printer after the offending laptop attempts to print.
Shutting down the offending laptop then frees up the printer for everyone else.
I noticed that laptops with the Atheros 5416 chipset work fine. They can print all day long, no problems. But when I switch to a laptop with the Broadcom BCM43xx chipset, it completely kills the printer.
I was able to get around this by using the Linux Open Printing drivers (HPIJS.) If I use the Linux drivers, the Broadcom laptops can print fine again.
The printer works fine over ethernet on any laptop, it only completely borks when printing via wireless.
I eliminated any cross-domain issues by placing the printer directly on the wireless subdomain; the Broadcom laptops destroy the printer over wireless regardless of the domain.
Maybe 10.6.3 will have updated HP printers. Damn it I hate these new HPs and their stupid host based printing.