printer scanner operation severely degraded in 10.6.8

I have 2 iMacs and a MacBook, all connected via an Airport Extreme; three printers: Canon MF4350d, Epson Workforce 500, and Lexmark S800. After installing the update for 10.6.8 on August 17, 2011, on all three Macs, printing and scanning has been awful, to non-existent. I got updates to 10.6.8 from We-Fix-Macs, but the fixes do not "stick."

1. Network printing no longer works.

2. Printing via direct USB connection works on iMac, not on MacBook.

3. Scaning on these "all-in-one's" is no longer supported by Apple's 10.6.8, except via Image Capture. I.e., neither Epson Scan nor Canon's MF Toolbox work, even after updating all drivers and all Apple software updates. Scanning on the Lexmark NEVER worked, despite restoring the system, resetting permissions, etc. That is still a complete failure on all Macs. iMac [7,1] and MacBook just does not see the Lexmark scanner.

All printers worked fine over network and via USB before "upgrading" to 10.6.8. Printer and scanner management has been severely botched in 10.6.8. It's as if Apple has just abandoned maintaining continuity for previous printer/scanner models, or did not pay attention to QA issues. Without a decent fix from Apple to their operating system, I expect to go back to 10.6.7 and a wait a year before doing any further upgrades. I'm not really interested in geeky work-arounds for Apple's failures. Everything but the Lexmark scanner used to work fine, over the network or via USB. I doubt I am the only person with this problem.