Try using the "License Borrowing" utility(search for it in your Windows Start menu).
It should also show at hte bottom what licences are issued and to whom - at least it does for us with a floating licence server.
there is a free tool available called LicenseUsage
It is a graphical user interface for the FlexLM status query and shows who is using which license in the network.
I think it was a thread here in the forum a couple of month (March) ago.
I have found it:
I use a macro written back in Nov. 2001 by a gentleman named Phil Bauman. Some of you real old timers might remember him. It creates a text file that looks as follows:
I would be happy to share it, but the other solutions offered here might be better. I have been using it a long time and it works so I never bothered trying anything else.