Time Machine sparsebundle corrupted on disconnect I've been using Time Machine over wifi and have had a recurring problem with corrupted sparsebundles. The scenario is a relatively new Airport Extreme, a MacBook with Leopard, and a partitioned Western Digital drive hooked up via USB to the Airport.

The backups work fine, if I'm just around the house, or if I remember to stop Time Machine and give it a few minutes to wind down before leaving. But if I just close the computer and run out the door, and am away from the network when I wake the computer, I come home to a corrupted backup, which generally cannot be repaired with Disk Utility (once or twice Disk Utility has been able to fix it).

This has forced me to delete my entire backup and start from scratch on several occasions. Is there any way around this problem, other than being vigilant about stopping backups before I leave?
Sadly this is why the Airport Extreme isn't supported for time machine. It doesn't have the smarts to repair the filesystem or handle a disconnect as reliably.  This isn't an issue with time capsules or a server than can clean up when the backup gets interrupted. 

You will have to nurse your setup as described, but the lifespan of sparse bundles on airport as USB disk are limited. 

Perhaps a firmware update or change to Mac OS X will make things better, but for now it's something to watch.