UPDATE: We have now released an update to iPartition and iDefrag Lite. We are still working on the iDefrag update.

There are a few known minor issues with Snow Leopard:

1. Snow Leopard uses compression for some files. If these become fragmented and you use the Quick (on-line) algorithm to defragment them, they will become uncompressed. Until we release an update we advise you not to use the Quick (on-line) algorithm.
2. In the Info window, iDefrag will display zero for the size of compressed files and they will have no data fork. This is just a display issue.
3. Both iDefrag and iPartition will crash at launch time when running on a 64 bit kernel. By default, only the latest Xserve machines will be running the 64 bit Kernel so it should not affect many people. You can easily work around this by booting with the 32 bit kernel instead: hold down the 3 and the 2 keys as you power on the machine.

Please be aware that it’s perfectly fine to run iDefrag on a volume that has Snow Leopard installed whilst booted from a volume that has an earlier version of OS X, and that includes any bootable DVDs you might have made. The issues above still remain though i.e. you still shouldn’t run the on-line algorithm on a Snow Leopard volume until we’ve issued an update.

We will be releasing updates to iPartition and iDefrag soon that should address these issues. Please report any other issues to us via our support team.