UBB.threads PHP Forum Software Community Forums UBB.threads Version 7/8 Support 404 / RSS errors

Every day, I get a load of 404s in my error logs.

http://www.example.com/forums/cache/global_rss4.xml

When clicking on the link I see the RSS feed but with missing images.

Right clicking on the missing image gives this...

http://www.example.com/forums/cache/%3C%3CGRAEMLIN_URL%3E/smile.gif

Any ideas how I can correct this?

Thanks