Thanks for the reply Greg.
Looking at the link you posted it doesnt appear to have the HP Designjet 500 - only similar ones with additional letters after such as plus etc. May be this is why?
I load the software fine, it appears on my printer list even with a green light. However as soon as i send to print the message states 'sending data to printer' however it then automatically goes into pause, the green light then turns to amber and the message says 'unable to send data to printer!
I have tried deleting the printer and the software with the printer folde rin libraries and re-loading but nothing works.
Apple say it is definately a driver issue and that i should talk to HP to ensure the correct driver is downloaded. However HP say that the latest 10.9 is the latest driver and because my upgrade is 10.9.2 it is maybe no longer compatible and that I should talk again to apple to provide a new driver that would solve this problem.
It's just really frustrating. You spend all the money on updating your technology and then other items which worked well before no longer function. I can also no longer wirelessly scan from the office network printer Ricoh Aficio MP C300SR since the new maveric operating system came out!!