Description 

I encountered a very odd behavior a couple of days ago, which turned out to be a very simple issue.

A fellow developer created a .ascx for me to use in my page. I have a gridview control with an *detail* button for each row.

This edit button is supposed to *pop-up* the user control which displays more detailed information for that particular row. For some odd reason, some postbacks of my, parent, page where suddenly disabled. One of them was the *detail* button.

Solution

To make a long story short, the cause for this odd behavior where validation controls on the user control. We solved the issue by explicitly setting the *ValidationGroup* properties of all validation controls and their associated user input controls.