OpenSSL private key error

I am trying to use some ruby library code to sign some material with my private key,. and I am encountering an error.

I have a private key as part of my SSL credentials from

I try key = where key is the File holding my private key

I get OpenSSL::PKey::RSAError: Neither PUB key nor PRIV key:: header too long

the first line of the .key file is -----BEGIN RSA PRIVATE KEY-----

The key works fine at my service provide - along with my .crt, HTTPS works and IE and FF recognize the credentials.

Any idea what might be wrong ?

I do notice that if I print out the file in irb, there are \n characters at the end of each line . However, I don't think that should be a problem.