I'm using MacOS 10.7.5.
I have tried removing the the Users/ApplicationSupport/Adobe/Dreamweaver/Configuration folder entirely, with both DW CS5.5 and DW CS6 - then re-install extensions with a new configuration. No other manufacturer extensions - Databridge 1.1.0 only.
Yes the site is properly defined as a php site.
Yes I have a site page open.