You misunderstand. The Nokia 6133 mobile handset is supported under Mac OS X 10.5 or later, but not under Mac OS X 10.4: using one requires the installation of a suitable plugin, which is not required for support under any Leopard release. It was the requirement for the novamedia plugin which I was indicating was not applicable under Leopard, because support for the device is provided by iSync 3.
Notice that the user who's message I replied to indicated that he was using Mac OS X 10.4.11. Your solution requires that he upgrade to a current Mac OX 10.5 release, a significantly greater cost than a Leopard upgrade, and one he might not want to make for unrelated reasons.