This issue exactly matches this Microsoft bug,
Due to one design flaw of IE 10 and IE 11, the original System.Web.UI.WebControls.ImageButton.LoadPostData implementation cannot handle the decimal numbers returned by such IE versions.
Microsoft released hotfixes for .NET Framework 2.0+, while we reviewed Mono's code base such issues are not taken into consideration.
One of my friend sent a pull request on GitHub,
That patch itself has some performance problem. Thus, I am now opening this bug report, and hope your guys can find a better way to fix it.