The first thing that you said ( That when you do a print from the printer display it prints fine but when you send a print from the computer it prints white splodges) That tells me that the printer is working and that the issue may be your file that you are sending. Try printing out some more internal prints from the display and make sure that the print is fine then send a print from you computer and then send a print from let say a word doc and see how that prints out. It just may be a file or software program.
I used a Word document and XP's Sample Pictures and got the same splodges each time. A friend suggested it might be a firmware issue -- but I can't find an update on HP's site.
The printer was chucked out by a local firm, I suspect for the problem I've experienced.
I'll keep working on it, taking your helpful comments into account.