The specified cryptographic service provider (CSP) does not support this key algorith

I get the follwowing error when using the .Net DSACryptoServiceProvider.
The code works just fine on our test IIS. Anybody??

The specified cryptographic service provider (CSP) does not support this key algorithm.

Here is the stack trace:
CryptographicException: The specified cryptographic service provider (CSP) does not support this key algorithm.]
System.Security.Cryptography.Utils.GetKeyPairHelper(CspAlgorithmType keyType, CspParameters parameters, Boolean randomKeyContainer, Int32 dwKeySize, SafeProvHandle& safeProvHandle, SafeKeyHandle& safeKeyHandle) +7715055
System.Security.Cryptography.DSACryptoServiceProvider.GetKeyPair() +86
System.Security.Cryptography.DSACryptoServiceProvider.ExportParameters(Boolean includePrivateParameters) +38
System.Security.Cryptography.DSA.ToXmlString(Boolean includePrivateParameters) +42