More based_on fixes.
More based_on fixes.

(Still missing copying/appending of data_table.)

darcs-hash:20070430183128-4eba8-7db3c7669d1eef69f01843293578ce5820c8d686.gz

dkogan/notion.xfttest,neg-serg/notion,raboof/notion,knixeur/notion,p5n/notion,p5n/notion,anoduck/notion,dkogan/notion.xfttest,raboof/notion,anoduck/notion,knixeur/notion,raboof/notion,p5n/notion,p5n/notion,dkogan/notion,neg-serg/notion,knixeur/notion,anoduck/notion,knixeur/notion,neg-serg/notion,dkogan/notion,neg-serg/notion,dkogan/notion,p5n/notion,dkogan/notion.xfttest,anoduck/notion,anoduck/notion,dkogan/notion,raboof/notion,knixeur/notion,dkogan/notion,dkogan/notion.xfttest