scanning issues in Lion OSX using Image Capture - flashing dotted box?

I'm trying to scan a document using imagecapture in Lion OSX. I can do an overview scan okay, the scan button is enabled. When I hit 'scan' all that happens is the dotted box around my selection item flashes bold. Nothing else happens.

What does this mean? nothing in the help file tells me and I have no idea what it's trying to tell me - no error messages, just a bold flashing dotted box.

I'm using a Samsung CLX-2160N MFD device.

How can I get it to actually *scan* not just flash annoyingly at me.