I recently discovered that the ImageButton and LinkButton ASP.NET controls do not function properly in Firefox 2.0. I wasted almost two days trying to figure out what was wrong with my code. Apparently, I was chasing a ghost! For more information on this problem can be found here. Unfortunately, the only workaround for this problem is to either upgrade to Firefox 3, which ROCKS by the way, or use a standard ASP.NET button and style it using CSS.