When I synchronize my data, repeating Tasks disappear. When repeating task items are transferred to your handheld, they are fanned to a maximum of three items in the device application. If you delete all 3 instances of a recurring task from your device, the corresponding repeating item in your PC application will be deleted the next time you synchronize your data. To avoid inadvertently removing a repeating item from your PC application, maintain at least one of the recurring tasks in the device. If you change a field mapping after you have already synchronized a set of data, the next synchronization is, in effect, a first-run synchronization, which may cause the duplication of records.
Duplications can occur if key fields are re-mapped.
For example, if you change the mapping of a Name field in the address section, address records may be treated as new records during the next synchronization because the records now look different from the records that already occur in your systems. Your PC database file has become corrupted. Your device is not reading or writing data properly during the data transfer. When I attempt to synchronize data, the operation is disrupted. Certain virus scanning programs can interfere with the synchronizer.