We have SHARP AR M165 printer in our office, and since we upgraded our computers from XP to Vista, we were having problems with network printing. We contacted SHARP service, but they couldn't find a solution either. Then after Google introduced its DNS service I set it to my computer and also to the main computer printer is attached I realized that my printer problem was gone.

So if you have a slow network printer connection like we had, you can just change the DNS address to Google DNS, which is 8.8.8.8 / 8.8.4.4. and see if it helps.

Also for a general rule, make sure that all the computers on the network have the same workgroup name.