Hi, this is a phantastic piece of software. After updating my Tiger installation this happened: If you manually delete iSync 2.0 (which comes with Mac OS X 10.4 Tiger) and then install the iSync 2.1 update, the application won't open. Its icon will become blank (a generic icon) when you click it. I spent weeeks to try to solve this problem and followed the advice Apple gives on it's support page which I think is not a very helpful advice (http://docs.info.apple.com/article.html?artnum=301926). By using Pacifist I SOLVED MY PROBLEM IN 3 MINUTES. 1) Delete the blank generic icon in your application folder 2) Download & install & start the program PACIFIST 3) Insert the Tiger system install CD 4) Click on "Open Mac OS X Install Packages" in the PACIFIST software and install iSynch 5) Now you can download the iSynch 2.1 update from the Apple website 6) After restarting your Mac everything works perfectly with iSynch Great job. I would give this software in all categories a 10 star rating if it would be possible. A Hungarian Mac User living right now in Germany - Christian Galli