Exception / hang on Mono.Security Diffie-Helman key generation for SSH Transport

[lanthias]

Hey guys, sorry for the very boring title..

I'm trying to do pushes through SSH. I am specifying my own keys by using the method set out here: http://stackoverflow.com/questions/13764435/ngit-making-a-connection-with-a-private-key-file

It works well with a clone, and on the first push. After that, it fails 30% of the time, always in this method in Mono.Security:

Mono.Security.dll!Mono.Math.BigInteger.Kernel.MinusEq(Mono.Math.BigInteger big, Mono.Math.BigInteger small)

Either it fails with the message: "Error occurred during a cryptographic function", or it hangs indefinitely in this function. Again, it seems completely random whether it succeeds or not. It is being called by function in NGit:

DiffieHellmanManaged dh = new DiffieHellmanManaged (pspec.P.GetBytes (), pspec.G.GetBytes (), 0);

in GenerateKeyPair (KeyPairGenerator.cs)

Any ideas? If not, are there any ways to generate the Diffie-Helman keys through some other method?

Thanks so much -- NGit is awesome!

Cheers,
Leo