Just to follow this up, if you replace the library file found at WA_DataAssist/library.php with the one that Ray kindly supplied you will find that next time you open the wizard it will be overwritten with the incorrect version.
The answer is to replace the library file found in these locations (Mac only perhaps someone could provide the equivalent windows location) with the new one Ray attached to this thread.
/Users/USERNAME/Library/Application Support/Adobe/Dreamweaver CS4/en_US/Configuration/shared/WebAssist/ApplicationBuilder/Helpers/library.php
/Users/USERNAME/Library/Application Support/Adobe/Dreamweaver CS5/en_US/Configuration/Shared/WebAssist/ApplicationBuilder/Helpers/library.php
This will ensure when you reopen the wizard the correct library file is written to WA_DataAssist/library.php
Hope that helps