I see someone else has had the same problem and it's not been answered, so here's another stab at it ...
I attach the camera, (EOS7D) to the computer, start up LR4, choose the camera as the source in Library module and click import - just like they say in the tutorials.
I can see all the photos on the camera's card in the grid view, but I want to check the quality and only import the good shots, so I double click on a thumbnail to go to loupe view, but the preview is tiny and if I re-size it with the slider at bottom left it is so pixelated as to be unusable.
Anyone out there with an idea of what's going on and how to fix it?
Come on! Make my day!