At 01:06 AM 9/25/2007, Shawn Wright wrote...
>I actually bled the rear again tonight, even though I hadn't
>opened anything back there. I guess some air had got past the
>proportioning valve when I did
>the calipers, as there was some there. Pedal is now good and firm,
>with no "droop".

It seems you've solved your problem, but for others who may be
following this thread:

I've had a similar problem, and noticed that the rear cylinders are not
level. Air can get trapped at one end, and won't be bled when using the
normal procedure. I removed the mounting bolt for the cylinder, and
rocked it back and forth while using a pressure bleeder. I also pushed
the pistons in while doing this (to drive any air toward the center,
where the bleeder is), and got some pretty good bubbles to come out.