Powering Power Functions Using a 9V Train Regulator

Calling all EE's, robotics nuts, technic gurus, PF fanatics, and electronics
geniuses...

So by using the PF to 9V connector wire, I can run a PF motor using the 9V Train
regulator.  This is all wonderful...until I try to put an IR receiver between
them.  When I do that, it doesn't work.  Can anyone explain why this doesn't
work?  I still have 9V going from the controller (it's turned all the way up) to
the IR receiver and then the motor connected to the IR receiver.  In theory...it
should work.  So...EE's and other electronics gurus...what am I missing?  Is
there a workaround?

For those wondering, I am in the process of motorizing all of my switches on my
layout using PF motors and IR receivers.  However, I would like to run them all
off of one or two Train controllers to eliminate the 'battery issue'.  

Thanks in advance for any help.

-Dave
ToT-LUG