Description of problem:
   Anaconda throws an exception looking for a callback action for the back
button when installing the latest (2007-04-01  also 2007-03-31) rawhide boot.iso
The attached anaconda dumps show the error.


Version-Release number of selected component (if applicable):
    anaconda-11.2.0.42-1

How reproducible:
    always on my test machine


Steps to Reproduce:
1. boot.iso from rawhide of 20070401
2. proceed as usual
3. see exception
  
Actual results:

    exception report.
    Note: the report to remote and dump to floppy buttons do not correctly
          operate to save the bug report.  I have to switch to console tty2
          and manually dump to floppy or scp the /tmp/anacdump.txt file.


Expected results:

    successful installation


Additional info:

work1.private: Pentium III (Coppermine) @ 600MHz   256Mo RAM
               MSI mobo with VIA chipset      RTL ethernet
               Trident Cuberblade/i1 AGP on mobo
               160Goctet Maxtor PATA hard drive, etc.