I have an idea. Oooh I have an idea and I hate when this happens. I have quite a few printers, two HP Deskjets 960cse, and more of a relic, an HP LaserJet 5L. All connected to one machine. Sometimes this happens when, say, you attempt to print from MS Word, and you click print, and the default printer is the 5L, although the printer you are actually printing from is the, in my case, the 960, you will get a load of characters, smily faces, and crap like that. Maybe you have more than one printer installed on your computer, not in the hardware sence, but like when you goto printers, there is more then one model. Um...if your printer does not have enough memory, this may also happen, although I don't quite know why. I run XP Pro and Office XP Pro also...um...try reinstalling your printer with updated drivers for it, if any, because winxp will most likely auto recoginze it...then just install the drivers, over what win xp gives you, even if they are the same. Also, see if you have a good connection, meaning that you should check if you your printer cable is firmly connected at both ends. Hope this stuff helps.
PS. Don't think its just your old printer doing this, my new ones do it too