Same thing here... There is a 700x320 image in the slider, and the posts also show up on the page area with a thumbnail. The thumbnail just takes a piece of the slider image, but often times, does not show what I want to have there. For example, if there is a car in the slider image, the thumbnail may only show a window of the car, etc.
How can I get it so that, the thumbnail can be of what I would like to show rather than some automatic selection?
I don't mind resizing and cropping the image in photoshop to 150x150, then uploading, but where and how do I get it so that new thumbnail image shows up rather than the automatic slider image selection?