When i gave Correct Answer also it is showing error message like "Incorrect Answer Please try it again." in Forgot Password.

Hi All,
I am doing Forgot Password.When i gave correct user Name it is showing Question & mean while it is asking answer upto here it's good.
When i gave Correct Answer also it is showing error message like
 "Incorrect Answer Please try it again."
Why i can't understand.Please give solution for this bug.
Here I am Using ASP.NET MEMBERSHIP
Thanks In Advance,
VenkiDedsai.
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