VANILLAICEE  This is a horribly supported product which I recommend people not even try to run. If you chose to you will only be frustrated and end up beta testing software that should not be released to the public.

The current version (in Leopard) will duplicate your all day events and improperly handles sync conflicts. The developer does not seem to prioritize testing before releases. Unfortunately GCALDaemon is not 100% in Leopard so I can't recommend that instead, but this program is not a solution for bidirectional syncing. Hopefully Google will release CalDAV compatibility soon and this program can die.  
(Version 1.1.1b)