I've noticed that the logs have the following entries:
[40267] (08/05 10:50:13.520):{0xD04} {<email>} Starting calendar rescan
[40136] (08/05 10:50:13.520):{0xD04} CalICSAgent::GetDirectoryName synch directory retrieved from registry: C:\Program Files\Research In Motion\BlackBerry Enterprise Server\Agents\ICSSync\ for <email>
[10007] (08/05 10:50:13.520):{0xD04} CalICSSynchronizer::Initialize - OpenProperty failed: (0x80004002)
[20041] (08/05 10:50:13.520):{0xD04} CalICSAgent::Start Could not Initialize Synchronizer for <email>: (0x80004002)
[30020] (08/05 10:50:13.520):{0xD04} {<email>} MAPIMailbox:

oICS ICS Start failed
[20280] (08/05 10:50:13.520):{0xD04} {<email>} DoICS() failed: ERR_FAIL
[40701] (08/05 10:50:13.520):{0xD04} {<email>} Calendar rescan completed
Does anyone know what could be causing the problem?
Thanks