No need to run ArtRage in XP compatibiity mode, it's a certified Vista application. So, you're running the latest version on Vista. Do you have any antivirus / anti-spyware / firewall software running in the background, and if so, can you let me know what software that is?
I'd recommend emailing me directly at email@example.com and we can go through some more detailed troubleshooting together to try and find the cause for this as well as get further details.
When you email me, let me know what version of Windows Vista 64 bit you're using, and what software you have running in the background at the time. If it's possible to take a screenshot of the Artrage window, that could be very useful, but if not, no problem. I look forward to helping further!