Crystal Reports [OutOfLicenseException]

I am developing reports using crsytal reports in vs 2005. it was working fine for few days, but after few days and after running it continusouly is started giving me OutOfLicenseException. i coudnt find any solution for that.

if any one of u have any idea about when this exception comes and how to resolve it, please send me email on : neeraj-jain@hotmail.com or reply to this post.

thanks in advance...