Problem with arcGIS administrator and licence switch

I have a local Basic (ArcView) key and I can have access to an advanced (ArcInfo) throught a remote license server. My problem is that ArcGIS Administrator don't save my license switch... I expain: I open ArcGIS adminstrator where the advanced license is check. The licence isn't checked in borrow/return section (so, I didn't locked it). I change the licence to "Basic (ArcView) Single Use". Press Apply and OK. If I open ArcGIS adminstrator again the license is back to "Advanced (ArcInfo) Concurrent Use". The technical service of my office came to verify my connection to the license server, to verify if I have a licence key in my computer. He also had reinstall completely ArcGIS and nothing have changed.

If somebody have an idea about where this problem come from it would be appreciate... My colleagues need the advanced key.

Thank