Buttons Don't Work After Validation

Hi,

 I have a couple textboxes on a form that are using the RequiredFieldValidator along with a button to submit the for to SQL Server.  When the pages first loads the buttons work fine.  However, if the required textboxes are left empty, and the validation occurs, after filling in the textboxes the submit button no longer responds to clicks.

 Anyone have an idea as to what may be wrong here?  Is it a property I need to adjust or may it be an issue in the codebehind even?

 Thanks in advance for the help! :)
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