Autoeventwireup has nothing to do with the button hanlders.It works only for Page Events. 

for more details see the article by using link below.

 
http://blogs.ittoolbox.com/c/coding/archives/autoeventwireup-attribute-9312

moredotnet

 

Check this out... http://forums.asp.net/p/932513/1096656.aspx

Also note that the default value for aspx pages in C# is true & for VB.NET is false.

HTH