Security.Cryptography.RSACryptoServiceProvider.Decrypt - cannot access a disposed object

Question

Our company has a web program to decrypt an encrypted string. The program works fine if not many requests calling it. If not (say over 150 requests at the same time), it runs into one of the following situations: 1) System.Security.Cryptography.RSACryptoServiceProvider.ImportParameters(RSAParameters parameters) at System.Security.Cryptography.RSA.FromXmlString(String xmlString) at ....... Cannot access a disposed object or 2) System.Security.Cryptography.RSACryptoServiceProvider.Decrypt(Byte[] rgb,Boolean fOAEP) at ...... Cannot access a disposed object I appreciate if anyone could point me to the right direction. Arch