I have an old form where some of the images (used as image buttons).  There are actually two sets of images. One Image is displayed for (button up) and another for (button down).  As the buttons detect a mouse down event the images are toggled. But some of the mouse down down images are transparent.  Not sure how they ever got changed.  How can the transparency be turned off? 

This is probably a general VB.Net (2008) question but I'm stuck.

Thank you.