My Time Machine tells me it cannot complete the backup to my Time Capsule because the backup disk image sparsebundle is already in use.

The 2GB hard drive on my iMac failed and has just been replaced under warranty.

When I got it back I restored my Time Capsule and started back ups of the iMac and the MacBook Pro.

Now 2 days later it is telling me that Time Machine couldnt complete the back up to my Time Capsule as the backup disc image sparsebundle is already in use. It is saying this for both machines which presumably means a problem within the Time Capsule.

What does this mean and what should I do about it?