>>Recently updated Firefox to the above (latest) version.
>>
>>My 'Select' elements are now behaving oddly. A single click often doesn't open the dropdown list. Mouse down and dragging downwards seems to work but is unintuitive. Also when the dropdown is open a single click on another area of the page does not cause it to collapse - a second click seems to be required.
>>
>>In fact, generally speaking, it just doesn't seem possible to interact with it in a simple fashion.
>>
>>Anyone else seeing this ?
>
>Do you have a sample URL where we can test this behaviour?

Fixed it. Apparently OMTC is supposed to speed up response but in some cases slows it down. Had to go to about:config and set "layers.offmainthreadcomposition.enabled" to false.

But that's not going to help users out in the wild who are unlikely to resolve the problem without specific instructions !!!

I'll get some testers to try it now they're awake :-}