Laserjet M2727 MFP has worked for years on a networked MacBook w/10.6. Now no driver can find the printer again after it's set up.
An iMac on the same network can use the printer fine.
The MacBook can use another HP Laserjet on the same network, and can access the M2727 on USB.
But the M2727 can not be found when the MacBook tries to print on the network, though it can be found enough to select it and set up a driver.