[quote user="rammam"]

 I'm not sure if you have figured this out yet, but I ran into something very similar yesterday and it turned out to be that the Grid had been disposed (It was on a form that had been disposed but hadn't properly released from memory due to other issues.)

So you may want to check that, perhaps you have the same issue I ran into.

Regards,

– Aaron.

[/quote]

I have just found this exact issue in our code – thanks for this solution, works great.