RSS widget not finding feed on another local virtualhost

I have WordPress and MediaWiki installed on separate name-based apache virtualhosts on our corporate network. However, the RSS widget in WordPress cannot pick up RSS feeds from the Wiki.

After two days of digging around in the code I think that I’ve worked our that the RSS widget uses rss.php, which in turn uses the Snoopy class to retrieve the feed. It seems that this only uses HTTP/1.0 and therefore doesn’t pass on the Host header required for name-based virtualhosts to work.

Are my guess above correct and is there a way of forcing the extra header information in? I was also trying to activate the debug routines, so I could work out what is actually going on. Where do those messages go – they don’t seem to appear in the source code.