Studio has taken a large leap backwards in 5.1

Mostly AJAX related
- trouble handling existing layouts from previous versions
- drag and drop and fields not sticking
- multiple fillers in the toolbox
- unable to edit panel names in some instances
- dragging a field from a row leaves the remaining field expanded but won't collapse, requiring a new row, delete the old one etc
- drop down editing of existing display values just doesn't happen

I use Firefox, Safari and IE - all exhibit different variations of what is and isn't broken