Dreamweaver is buggy, but I am used to the bugs since I have been using it for so long.
I was getting this issue with cs5.5 so I said F it and upgraded to cs 6. Same error in cs6
It appears to only be happening with this one particular site.
I created a new DB user, a new connection script and changed the ftp password . I even nuked the site out of my site list, deleted all connections scripts and recreated it but it is still throwing this error when I try to apply a repeat region.