wired button post-back bug

It is now twice that I have encountered this problem, so I decided writing about it. Why does click on <button> HTML controls, generate two post backs and the weirdest thing is, it is doing this at random ,.. You can only see it using fiddler, but I have no explanation for it. The bottom-line you should be careful using <button> HTML controls in you code, and try to use <asp:button> or  <asp:hyperlink> in stead.

With some CSS you can style those to look just like buttons.