Something wrong with .fasb support

A test in the ASDF test suite reveals brokenness in ECL fasb support.

cd .../asdf
make t l=ecl t=test-xach-update-bug.script

==> It works!

Now try again after uncommenting this line near the top of the file:

(setf asdf::*load-system-operation* 'load-bundle-op)

==> It fails!

The problem seems to be a conflict in package handling when trying to load from both fasl and fasb, or something.