Description of problem:
Any attempt to execute a 32bit compiled application on an x86_64 Fedora 9 xen
guest fails, both Fedora-supplied applications and 3rd party applications. 
Crashes with "cannot execute binary file", strace dumps "write(3, "strace: exec:
Exec format error\n", 32strace: exec: Exec format error) = 32" very quickly.


Version-Release number of selected component (if applicable):
Running Fedora 9 guest on RHEL 5.2 host, both x86_64 and fully patched, Fedora 9
guest with kernel 2.6.25.3-1.fc9.x86_64.xen.

How reproducible:
100% reproducible.  Happens every time.  Problem not visible on identical x86_64
bit installation on desktop machine, problem also not visible on Fedora 8 or 7
x86_64 guest installations.

Steps to Reproduce:
1. On 64bit host, try executing for instance /usr/bin/mbchk from
grub-0.97-33.fc9.x86_64 - but any 32bit application will do.
  
Actual results:
It crashes.

Expected results:
It doesn't crash. :)

Additional info:
The only difference between the xen guest and a normal installation should be
the kernel, so I suspect there's a parameter in there not set?