Treo 680 problem: palm desktop copied files (from old desk..

I have just bought a new treo 680 to replace my old treo 270.
All the installation went fine (even the import of my data on the new
treo).
But, the palm desktop software crashes.
The only way to make it not crash is to replace the memo, address, to
do and contact lists with the empty original plam desktop files.
But, when resynchronising or recopying the memo, address, to and
contact lists from my old palm desktop, palm desktop crashes again.
In concluson, I have the memo, ... data on my treo, but palm desktop
systematically crashed when it has this data.
What do you think can be done to solve this issue?

Thanks,
Marcel.