Errors while trying to view some topics

[iGuest 3]

I have been receiving an error when trying to view some of the topics in the forum >>>>> The XML page cannot be displayed Cannot view XML input using XSL style sheet. Please correct the error and then click the Refresh button, or try again later. --------------------------------------------------------------------------------Whitespace is not allowed at this location. Error processing resource 'http://forums.xisto.com/?...<link rel="chapter forum" href="http://forums.xisto.com/no_longer_exists/" title="BulletinBoard & phpnuke" />--------------------------...Anyone know what I can do to fix this?