same problem here. Dataassist 2.0.5 crashed when install in Mac OS X.5.7 with DW CS4.
Revert back to version 2.0.4 temporary solved the problem.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.