Master page_enableeventvalidation「建议收藏」

I have the following scenario:

I am using a masterpage (masterpage.master) which contains a textbox and two Imagebuttons as server controls. I tried some non-input content pages using this master page and everything is OK.

However, I have recently added a new content page which consists of an <asp:Wizard> and its steps, one of which contains <asp:textbox>es and some validation controls. The problem I am encountering, is: if the initial value of the textbox(es) is, say “abc” (set in <asp:WizardStep> html), even if I type this value to say, “hello” (when running) and put a breakpoint in the content page’s Page_load to see the value
after postback, it is still given as “abc” (even though I have typed “hello” in the textbox(es)).

I also noticed incidentally that if I remove ‘EnableEventValidation=”false”‘ from the masterpage, I get “Invalid postback or callback argument” error.

What I do not understand is that if I remove the master page (or use a different page with the content pasted in and no masterpage included) the change is registered after postback.

Could anyone please help?

Thanks in advance,

Timothy