Hello!
I have the weirdest problem ever..!!
At the very end of chapter 2...I have the theme selector drop-down, and I have two pages: Default.aspx and Contact.aspx. Contact.aspx is a really small & simple page with just one text field in it...

When I test my "beer" app in Mozilla browser, everything works like a charm..I can switch between two themes in both .aspx pages, no problems. Everything builds and compiles and there are absolutely no debugging errors.

However, when I run in Internet Explorer...When I try to switch between themes in Default.aspx, the themes are NOT switched and nothing happens. And when I try to switch between themes in Contact.aspx, Internet Explorer explodes all together, and yeilds the following meaningful output:

************************************************** *****************
Server Error in '/TheBeerHouse' Application.

Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentException: Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[ArgumentException: Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.]
   System.Web.UI.ClientScriptManager.ValidateEvent(St ring uniqueId, String argument) +358
   System.Web.UI.Control.ValidateEvent(String uniqueID, String eventArgument) +108
   System.Web.UI.WebControls.TextBox.LoadPostData(Str ing postDataKey, NameValueCollection postCollection) +22
   System.Web.UI.WebControls.TextBox.System.Web.UI.IP ostBackDataHandler.LoadPostData(String postDataKey, NameValueCollection postCollection) +11
   System.Web.UI.Page.ProcessPostData(NameValueCollec tion postData, Boolean fBeforeLoad) +380
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2965
************************************************** *******************

Does anyone happen to have an idea why would this be happening ? Like
I said, there are no compiling/debugging errors...

Thanks a bunch for any feedback,

--fluffy

Actually, I managed to get rid of that long "error stack" that Internet Explorer has thrown at me, by adding the "EnableEventValidation="false""
attribute in the @Page directive of Default.aspx. I'm not sure whether
that fixes the problem per se, but at least i made it go away..
:)
But the themes still don't get changed in Internet Explorer...Is there
any way to debug this matter ???

thanks,

--fluffy

You should not have to set that to false. Did you try the code in the code download?

Eric