Server controls persist their state when EnableViewState is set to False
I was wondering about the presence of viewstate after making false to EnableViewState.This is by design :)
Here is the details....
This behavior occurs because the ViewState of a control is only one of the methods that are used to persist a control's attributes across requests. In the server controls that are mentioned in the "Symptoms" section, attributes that are not normally posted to the server through the form-get or the form-post are handled by the ViewState. These values include attributes of the control, such as BackColor. Attributes that are normally posted to the server are handled by the IPostBackDataHandler interface. An example of such an attribute is the checked attribute of the CheckBox control.
For more ..
http://support.microsoft.com/kb/q316813/
Cheers..
Suresh Behera