My windows profile has a valid EFS certificate (with appropriate EFS flags) and when I try to encrypt a file with Windows Encrypt() method a new certificate is generated instead of using the one I imported. When I test it with dev certificate (the same set of flags) it works.
What could be the problem?
Ok, the problem was with expiration date of the certificate, which was too far in the future. For Windows OS the certificate is valid, but EFS system rejects certificates with expiration date further then about 20 years.