Thanks to Rohan Lean from Business Mobility Solutions, a file locking problem has been found when PGP encrypting using the EncryptFile method. The solution was using FileShare.ReadWrite mode. .NET OpenPGP Library has been updated Thank you Rohan.
A .NET OpenPGP Library is available for download. The Library is entirely in managed code, with no other dependencies. The library is compatible with OpenPGP standard and GnuPG and PGP(r) implementations. For details see the homepage of the .NET OpenPGP Library.