Hi,
You can try XTNDConnect PC from Extended Systems. We use it at our office and it works perfect. (R4, R5 and R6)
Not only synchronizes it with Notes, it als synchronizes with Outlook and several other PIM's. (
http://www.extendedsystems.com/ESI/default.htm)
It's easy to use and very easy to install.
The interface of the program looks like the old Easysync from lotus.
Bas Auer