F8 rescued fails on FC7?

[Mike -- EMAIL IGNORED]

On my dual boot laptop with WinXP and F7, if I try
to start from the F7 rescued, it appears to run
properly.  However, with an eye toward installing F8,
if I boot from the F8 rescued, it hangs after printing
the line:

running /sbin/loader

The downloaded rescued iso passed sha1sum, and I tried
it with two different burned disks.

!!Now while typing this, perhaps five minutes later, it
suddenly started correctly!

So what took so long?

Thanks,
Mike.