[Juha]

This is the reason i moved to illustrator + indesign;

I can have master design in different file, and export all the states and screens as individual files.
Then i can link the individual files to various other documents; concept docs, visual design docs, functional prototypes.
If a icthy bitchy detail changes, I just re-export and relink files, which should take a few second instead of several hours.

This allows me to have on 'Master design' file, and different files for different communication needs.

I'd love to see ability to link files instead of embedding them, I might get back to graffle.