Incredimail Registration Code is Invalid

Hi. I purchased Incredimail and tried to install it on my Windows XP PC.
When I entered my registration code, I received an error saying that it is invalid.
I typed the code correctly for few times now but the error still exists.
How can I fix this?
I posted a screenshot of the error.
Please help.

IncrediMail Xe
Invalid registration code.
Please make sure that you have entered the correct code.
