Below is all of the information I reported to Mozilla.
I installed Firefox 1.0 last week. There are two printers on my home network.
One printer is directly connected to one of the PCs and works fine. The other printer (HP LaserJet 5) is connected to a Dlink Dl704P-B1 router. Once Firefox installed that printer began misbehaving. Now when I try to print a document, from either PC, the first page contains what appears to be printer commands, then the document prints. Unfortunalely, when printed the document is missing text, characters are over-printed and sometimes, depending on the document, strange characters are included. If the same document is printed on the directly connected printer (HP LaserJet 6100 all-in-one) it is fine. I disconnected the LaserJet 5 printer from the network and connected it directly to a PC then it printed the document correctly. Also, I downloaded and installed all new printer drivers but that did not help. Lastly, I download and installed the current software versions for the DLink router but that did not help. I used Microsoft's "Add / Remove" software to remove Firefox from one of the PCs but that did not help. Also I noticed Firefox does not come with an uninstall feature to remove / reset Registry changes. My suspicion is that Firefox changed a setting in the Registry not expecting to come in contact with a faily old HP LaserJet 5 printer.
As far as the printer being set to "raw" mode, there was/is a page on www.hp.com that talks about this exact problem and part of the fix indicates that the printer should be set to "raw". When I get to my office on Monday I will provide more info about this. I tried to re-locate the page on HP but could not.
Thanks