There is a temp directory, and just to eliminate any potential permissions issue, I went onto out Windows IIS Server (logged in as domain admin), and opend the website on there, and tried to print a ticket, and still got a 500 error.
Have checked the folder, and as an Admin on the server itself no reason that permissions should be an issue.
Can't see what has changed as we just did a straight upgrade from 1.10 and ticket printing was fine then....it was the one thing I didn't test on the system before upgrading the live one...
Other people who don't have the issue, are any of them running a wimp stack? (No not a wamp, we run a wimp windows, iis, MySQL, php)
Any ideas and all your help so far greatly appreciated...
Dave