imaps connections no longer working after ios5 upgrade

Hi

I upgraded my ipad to IOS5 today. After this, connections to our imaps mail server is failing:

Oct 12 18:39:14 umdgrb dovecot: imap-login: Disconnected (no auth attempts): rip=xxx.xx.xx.xx, lip=xxx.x.xx.x, TLS handshaking: SSL_accept() failed: error:1408F119:SSL routines:SSL3_GET_RECORD:decryption failed or bad record mac

Server runs debian 5.0.8 (dovecot v 1:1.2.15-7)

and ios 4.x device is still working fine.

Anyone have any ideas?