Strange hotbar error

[Pezander]

This has only been happening since the last few patches.

I have 6 hotbars on top of each other in the bottom center of my screen. The top bar is the only one exibiting this problem.

During any fight in a Raid, the 1st 9 buttons of my top toolbar (bar 6) become unclickable!! i can release them by clicking button 10 and cancelling the spell, buttone 1-9 can then be clicked.

When this happens, there is no mouseover effect on the buttons and they do not move when clicked.

Told you this was strange!

What will i need to do to gather information for you to diagnose this apparent issue? Screenshots sown nothing but the position of my bars.