I’ve had an issue with setting fields widths, eg. I width to 50% so I can put another field beside it, the side by side fields are no longer selectable i.e. clicking on them does nothing.
With no Width setting the fields are selectable.
However, it appears this issue ONLY appears if the side by side fields are directly above a set of tabs. In that case the ul.tab-group element seems to extend upward and encompass the 2 side by side fields above. (determined this using Firebug to select the various elements)
Adding a blank Message field with no width set between the tab set and the side by side fields resolves the issue for now.
Thought this was worth mentioning as it would be great to have it sorted out.