Hi,
To better understand your issue, please clarify your issue in detail? If the breakpoint is not hit, please make sure the debug is configured to true in web.config.
If Visual Studio debugger cannot attach to IE, you can try to use Visual Studio debugger to attach to it and debug it. For more information, see How to: Attach to a Running Process (http://msdn.microsoft.com/en-us/library/c6wf8e4z.aspx).
Since you are using IE 8, please refer to http://social.microsoft.com/Forums/en-US/vsdebug/thread/e2c795cd-b7a0-4fad-b7c9-b1ca40d7302e which discusses the debugging issue related to IE 8.
I look forward to receiving your test results.