Outlook Sync: limited number of records?

Hi all,

- NAV 5.0 SP1
- NAS running on appserver
- OutlookAddin running on citrixserver

I managed to setup Outlook Sync monodirectional NAV --> Outlook for following entities
- APP (Appointment Item)
- CONT_COMP (Contact of type COMPANY)
- CONT_PERS (Contact of type PERSON)
- CONT_SP (Contact of type SALESPERSON)
- TASK

all running fine and without any errors \:D/

But when the number of records transferred from NAV to Outlook exceeds the number of 249, Outlook throws following error:
'An error has occurred during the synchronization process. You can find the error details in the log file. Please contact your System Administrator'.

I already changed the Object Cache on the NAS from 32000 to 128000, no change there.

Upon checking the Job Queue Log Entries, the following entries are posted for the transaction:
- CU 5306 (Outlook Synch. Export Schema) : no errormessage
- CU 5308 (Outlook Synch. Synchronize All) : no errormessage
So OutlookAddin tells me to check the log file, ... but it mentions no errors ](*,)

in a normal sync, also following steps occur, but these are not listed in the Job Queue Log Entries in case of the error
- CU 5309 (Outlook Synch. Process Links) : no errormessage
- CU 5311 (Outlook Synch. Finalize) : no errormessage

Has anyone encountered the same situation: limited number of records transferred from NAV to Outlook?