3TB time capsule not working with new iMac
I have a 3TB time capsule that's c. 2 years old. It worked perfectly with my old iMac. I bought a new 27" one when it came out this year and since the time capsule will not work.
I had to clear all the data as a starter. Now it gets a little into the backup taking c. 1 day then resets. It's connected via ethernet cable and has been told to join an existing network.
Currently it says it's backing up 922,498 items, after 2 hours (this is the third attempt, it resets then has no record of the old backup) it says 10kb of 789.44 GB - About 4,664,440 days remaining!!
To clarify I'm trying to use Time Machine with the Time Capsule.
Please help!!
Time Capsule-OTHER, OS X Mountain Lion (10.8.2)