well if you already know what it's not - why ask ?

Have you tried printing the file a lot smaller ? say 25%
That way you should be able to rule out the file and usb connection.

Also we know you haven't had this problem before.
So saying 'it can't be that, i've never had this problem before' - without testing it doesn't help any of us.

Trouble shooting is a tedious process that involves ruling things out one at a time.
It's entire;y up to you whether you do it or not.