We have a DotNetNuke2.0 application.
We have added a new module - ProductList.ascx, which contains a panel and a command button called 'Next'.
In the panel another usercontrol - Product.ascx is added dynamically. Product.ascx contains an image button and on click of this image button, a new window is opened as a pop up.
After closing the window, when we click on the 'Next' button of ProductList.ascx we get the following error -

Failed to load viewstate.
The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.
For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.

Note, if we do not click on the image button and directly click on the 'Next' button of ProductList.ascx the above error does not occur.

If we login as a host and perform the above steps we dont get the above error but for any other registered user we get the above error.

Why is it so for the host we dont get the above error?

Any help will be appreciated.