After enabling Time Machine over the network (Airdisk) I realise that one of the issues that will most certainly lead to backup data loss is sparsebundle management. Basically, Time Machines creates a .sparsebundle on the destination volume (airdisk or whatever..). once Time Machine is about to backup or restore, it mounts the network volume and also the sparsebundle volume within it. Now, if the network conection drops, the whole sparse bundle gets corrupted and all data is lost. It doesn't happen often (in fact I use .Mac Backup over airdisk and the same thing could happen but never has). Another thing is that Time Machine does not unmount the sparsebundle once it finishes using it. It is a problem if you forget and don't unmount it manually. You could put your mac to sleep while the sparsebundle is mounted. I've been doing test with dummy sparsebundles and this leads to corruption about 50% of the time. Apple could easily fix the latter by ensuring the sparsebundle volume is correctly unmounted upon completion. The former I'm not so sure.. I don't like the idea of using sparsebundles in the first place (like I don't like the ideas of sparseimages for FileVault.. a simple Kernel panic leads to corruption of all data.). How did Time Machine over Airdisk work in the betas? Was it through a sparsebundle or writing directly onto the airdisk volume?