Early License Returns

I have never been able to get a borrowed license to return early from any of our workstations. We have tried changing the versions of lmutil, lmgrd etc and this didn't help. We tried closing down all other services which used the FlexLM manager whilst trying to return a license and this didn't work. I have been through all the posts on this board and tried each and every offered solution with no joy and then today I thought I'd give it a whirl just using the DOS interface. Using this method, I am able to return licenses every time I try, without fail.

As I am able to return licenses using the command-line, am I to assume that the problem I (and many others) are experiencing is something to do with the Windows GUI?

I know I could ask everybody here to use the command line to return licenses but knowing how some people get spooked at the thought of DOS, I'd much rather be able to get the GUI working if at all possible.

Can anybody provide any pointers?