Update your cryptographic settings before August 2012 software update!
Coming August, Microsoft will be releasing an important update that will block all applications that use cryptographic keys less than 1024 bits. To further reduce the risk of unauthorized exposure of sensitive information, Microsoft has created a software update that will be released in August 2012 for the following operating systems: Windows XP, Windows Server 2003, Windows Server 2003 R2, Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2. This update will block the use of cryptographic keys that are less than 1024 bits.
To read more and find the issues that you may encounter after applying this update go here - http://blogs.technet.com/b/pki/archive/2012/06/12/rsa-keys-under-1024-bits-are-blocked.aspx