Printing Anomaly- a strange phenomenon

Hi

I use Wind XP + a HP PSC 500 printer. All was working
well until recently [ possibly until after an automatic
Windows update].

A strange phenomenon now occurs: I can print old
documents [ from any source eg notepad, word] ok, but new
documents [whether saved or in RAM] appear to print but
all I get are blank sheets [as if the cartridge is
empty]!! Reinstalling the print driver was no help and
the problem is not dependent on the wordprocessing
software used.

Anyone come across this before and can help. please
contact.

Thanks

Martyn