forcing fcpx to create proxy

I am editing a video complation in HD ( 1080p ) on an iMac 27inch i7, 2GiG video card, lots of RAM ... FCPX. I had to set the playback to proxy when effects and media streams added to ridiculous levels.

I have some old VCR footage that captured into FCPX through FireWire of an older DV-cam. I am getting red screens for those clip for missing proxy media. When I go to the offending media to transcode to proxy, both options of a. create optimized media and b. create proxy media are greyed out !

I understand FCPX is telling me that my system is powerfull enough to edit the SD footage as it is. But why the heck it doesn't render the SD footage for be used in lowend playback ?

Is there a way to force FCPX to create proxy media ?