The lastest update for Snow Leopard 10.6.8 replaced the entire Common Unix Printing System (CUPS) and in this process has created a lot of problems with printing and compatibility among printers.   This can mean some serious lost productivity if you find yourself in an situation where you and co-workers cannot print after the update.  Here is a fix, sorry for the multiple steps but you got to do what you got to do.
Review these frequently asked questions for OS X 10.7 Lion and Mac OS X 10.6 Snow Leopard printer support. What driver options are available for OS X 10.7 Lion? With the release of OS X 10.7 Lion, HP is providing updated print drivers and software for your printer. My iMac operates Mac OS X version 10.6.8. My new HP Envy 7640 printer does not have a driver to support this version of the Mac operating system. Is it easy to upgrade to a more recent version an iMac OS or does anyone know where I can get a driver for Mac OS X 10.6.8?
1. First Download this file.  (CUPS) engine from 10.6.7 (which worked perfectly).cups
2.  Now Extract this zip file and take the cups directory and place on your desktop.
3.  Now Click on the Finder icon and then up at the top of the screen click on GO | GO TO FOLDER
4.  No type in the box  usr/libexec
5.  In the Finder window that pops up first locate the cups directory and then drag it to the trash.
![Mac Mac](/uploads/1/2/4/8/124879898/751408783.png)
![For For](/uploads/1/2/4/8/124879898/858169575.jpg)
6.  NoNow drag you cups directory you placed on the Desktop from the downloaded file above into this /usr/libexec directory you have open in the Finder windows.
10.  Now launch Disk Utility  (May be easiest to just use Spotlight and search for it)  (otherwise is in Applications | Utilities)
11.  In Disk Utility Click on your Macintosh HD and then click on REPAIR PERMISSIONS. Let this complete can take anywhere from 5-20 minutes and you are all set.
12  You can now print again like you used to before the update :)  To be extra safe you may want to restart the computer.