Slow but easy way to do it is:
From your Master server1) Click on Host Properties-> Clients
2) Highlight EVERY Client
3) Right Click->Properties
4) Go get some coffee as it will take a while (We have about 460 clients and it takes an hour or more)
5) Come back and hit CANCEL on the dialog (unless you want to change any properties globally like exclude lists etc)
6) Now you can sort by the VERSION column to get all the versions for your clients
AK