I'm very happy of my shiny new 2TB Timecapsule : I use it to backup all my Mac contents.
1 MacMini (latest model) with 10.6.2 (wifi) 1 MacMini Dual Core 2 with 10.5.8 (ethernet) 1 Mac Pro OctoCore With 10.5.8 (ethernet)
the first setup and weeks happened fine, all was simple and fast to configure.
But since last reboot of MacMini 10.5.8, Finder shows a device name that appears during backup and mounting of backup drive... and this device never desapears just like a ghost from the device list in the sidebar. At the end, if I don't drag and drop those ghosts out of the sidebar, I have as many ghosts as I had backup.
In fact, when Time Machine starts backup, a disk with a regular white icon named "backup of MacMini" mounts AND another image as shown in the picture appears. Then Time Machine stops backup, ejects the primary backup (white generic icon of a drive), but the ghost grey icon of a drive stays. see here http://xzu.free.fr/m4e/ghosts.jpg
since everything happens fine on the other MacMini 1.6.2 and the MacPro 10.5.8, I don't see what is happening and how to remove that without going back to 1st day (the big first backup via Ethernet).
Also note that the Time Machine backup file of this MacMini is not repeated nor huge. Just in case someone would believe Mac Mini is making new backup everytime.