My wife has a Macbook OS X with 2.4GHz processor, 160GB hard drive and 2GB ram. There is only about 30GB worth of stuff on the computer including the OS. It used to back up relatively quickly (as does mine which is identical). It has now started to back up very very slowly using the Time Machine. By slowly I mean it took about 5 hrs to back up 5GB. She 'phoned Apple as it has Applecare but the bloke on the other end didn't seem to be of much help.

Any ideas as to why it should be so slow. The machine is only about four months old.