[RESOLVED] Buttons unclickable

[chris128]

I've got a weird problem... I have a few buttons on my form and after disabling and re-enabling all of the buttons, two of them cannot be clicked. Here is the form in question:



The two buttons in the bottom right corner - Import and Cancel - cannot be clicked after I set their IsEnabled property to false and then back to true again.
The weird thing is that I am doing the exact same thing with the other buttons on that form but all of the others still work fine. I have tried just sticking a new button on the form right next to those two and that new one works fine...
Just to clarify, the buttons do not look any different when they are unclickable - they dont look disabled or anything, but when you mouse over them you do not get the normal mouse over effect that buttons give.
To make it even weirder, if I tab to the buttons and then use space bar to press them they both work fine!

I am baffled!

Any ideas?
Need any more info?

Cheers
Chris

EDIT: OK I just found that even if I dont set the button's IsEnabled properties to false and back to true then this same problem occurs anyway :S The thing that seems to trigger this is clicking the Generate Preview button in my app, which runs a background worker that populates the ListView. It doesnt touch the Import or Cancel buttons though so I am rather puzzled...