For most of my images, it used to be that when you clicked on it the link would send you to a larger size of that image. I would normally set it up this way so that the image (sometimes with charts/numbers) would not take up much space in my post, but could be enlarged for careful inspection.

Now, when you click on the image you are taken to a smaller size version of it. It's seems to be a consistently small size. This is a problem because it makes many of my charts or similar images unreadable.

Typically I upload a "full" size image, then shrink it to make it smaller so that it will fit in better with the post. However, I did a test post and kept the "full" size image, but it also shrinks when clicked.

Here's one example: http://costofcollege.wordpress.com/2012/01/11/for-job-security-its-better-to-make-technology-than-to-use-it/
Another: http://costofcollege.wordpress.com/2012/03/21/purdue-scholarship-chart-spells-out-basics-but-the-devil-is-in-the-details/

I use Under the Influence theme. Any ideas about what has happened and how I can fix this problem?