Trying another version of desktop manager isn't going to hurt.
I think you need to take a look at the data. On your desktop organizer, change the calendar view so that you see the data in spreadsheet/tabular format. Look for any strange characters, any empty rows, and delete. And then re-sync one-way computer to blackberry.
In the future, I you could also inspect the blackberry data by doing using ASCII Importer/Exporter setting to export the calendar or whatever to a spreadsheet and then look over the data.
In this instance I thought was just easier to delete the database and re-sync. But it appears the trouble may be with the database on the desktop organizer. At least if another version of DM dosn't work, that's what I would assume.