Vista - Virtual Machine Manager and ISO images

The company where I work is to introduce Virtual Machine Manager to be used
to host Virtual Machines for a test rig for the CD ROM products that they
produce. It was intended that we would access the CDs as ISO images. We
have found that when attaching an ISO image to the virtual CD drive that the
VM restarts. The whole process is very time consuming and has to be
repeated each time the CD is changed. As we have to test many CDs a day
this is a problem. Is there an easier way?

Thanks