At the top of this forum, there is a little person, and it says "User Settings" - click on that.
Now, scroll down to "Edit Options" and click on that.
Scroll down a bit more until you find a box with this text:
Visible Post Elements
You have the option to show or hide various elements of messages, which may be of use to users on slow internet connections, or who want to remove extraneous clutter from posts.
There is a check box to veiw images that are embedded w/the [img] code, you need be sure that box is checked.
Should be good after that!