Since upgrading to Mavericks my Interface and hard drive are shutting down when Mac put to sleep

Hi,

Since upgrading to Mavericks, when I put my Mac to sleep both my audio interface and my time machine hard drive are put to sleep also. Effectively making it so that when I start up my macbook again it means removing both the aforesaid from the usb outlets and putting them in again so that the mac recognises them.

This means two things. First of all all my time machine backups fail that are attempted whist the mac is put to sleep, whereas before they succesfully ran. It also means that my audio interface does'nt work and has to be re-set.

Anybody have the same kind of USB / Sleep issues?

Many thanks in advance.