[Dovecot] Courier to Dovecot migration script issue

[xnasx]

Hi!
Forgive my bad English.

I trying to migrate to Dovecot 2.0.18 from Courier 4.10. 
I using a script 'courier-dovecot-migrate.pl' from oficial wiki - it works without errors and creating dovecot-uidlist, etc. .

I running Dovecot on a different port: 11149.
When I connecting to port 11149 from Thunderbird, all my message headers are reloading.

Please help me to solve this issue.

Best regards,

Victor