Use the [caption] shortcode:

http://justintadlock.com/archives/2011/07/01/captions-in-wordpress

It’s back up.

I disabled plugins, then completely closed and reopened the browser.

What could make such a thing happen?

Part of an answer:

The Custom Image Size setting determines the dimensions of the image sent to the browser, not the size at which it is displayed.

A file sent at 180×180 will be grainier than one sent at 450×450, if the image has to be up-scaled in the browser to fill the column’s width.

I still don’t see the algorithm used to create the image file. Sometimes the image is cropped and sometimes it is not.

Josue, did you get this web address I posted? Can you help me out?

Thanks.