[Dovecot] problem with server certificate: dovectot.pem

[vladone]

Hi!
I have an mail server with postfix and dovecot.
All works fine, but now is change my domain. After changed
configurations i can receive (or send) mail without STARTTLS,
but when i try to use this option i receive:
 "TLS handshake failure. Invalid server certificate (Key material
 mismatch)"

 I dont know what is this.
 I use certificate that is generate with script for dovecot (that work
 at begining).
  Even i try to rebuild this certificate acording with new domain but
 nothing.
 Where is my problem?
 
 P.S. All works before changed my domain!!!