If you'd like to report any bugs against the software which is available from this site then please consider seeing the software-specific bug reporting pages.
By reporting a bug to the appropriate mailing list you'll most likely receive assistance from people before I've gotten round to reading it.
If you think the issue you have isn't suitable for public consumption, and you're happy to wait for a reply, then contact Steve:
The Debian Administration website contains several useful articles on using Xen upon Debian.
If you have any questions about running xen-tools please feel free to contact the author.