Nod32 and Kerio Offline Connector - very slow

Hello,
i have a little problem in a company using Kerio Mail System and like 50 workstations (WinXPP) connected with Kerio Offline Connector.
We upgraded from Bitdefender 9 (aka the trouble maker) to Eset NOD32 so far so good. Windows seems really to works faster now - but if you want to open Outlook 2007 (with Kerio Offline Connector) you need like 5 - 45 !!! minutes until you able to read or write emails.

Is there a known problem with Kerio Offline Connector and NOD32 ?
..or you got any recommended settings for me to speed up Outlook 2007 again - maybe without losing too much safety in NOD32 ?

The Kerio Mail Server is also protected by NOD32 as far i know (we only have a service contract for the clients so we don't have real access to the servers)

Thx