At each connection, ActiveSync asks to create a new partnership.

It's possible that ActiveSync has an internal problem with its synchronization table.
You may try the following operations:

- Delete you ActiveSync partnership on both the desktop ("ActiveSync/Tools/Delete mobile device") and the mobile (ActiveSync/Menu/Options)
- After having made a backup, delete the following directory:
XP: C:\Documents and Setting\\Applications Data\Microsoft\Activesync\Profiles\
Vista: C:\Users\\AppData\Roaming\Microsoft\ActiveSync\Profiles\
- Reconnect your mobile and configure a new synchronization