Hi, i had the same issues and fixed them myself. I wrote about it here: http://phillashcroft.com/?p=24 If you need more details let me know and we can surely work them out.
I just had some issues with this plugin breaking the Twenty Eleven theme and worked them out. I wrote about what i went through and how i fixed it here:
http://phillashcroft.com/?p=24
If you need more details let me know.
The way that the Plugin is pulling the photos is most likely the reason, it uses the url of the plugin for the beginning of the URL, then appends what you have entered in the .xml file to that. This isn’t mentioned anywhere, but the images HAVE to be in the plugin directory (mine is /var/www/phillashcroft.com/wp-content/plugins/header-slideshow/resources)
