Hi Rohann,
Look into getting the Exchange license purchased and loaded up. This will allow you to backup the Information Store while it is live.
I think there seems to be some sort of issue with remounting the Exchange IS, and you can look into that. It is obviously a pre/post command that gets run to dismount/remount the IS.
However, it might be worth your while to get the client to upgrade to the latest version of BEWS as well, as 10D is outdated.
Laters!