Kieth I am with you; If they are using Land Desktop, they should only be launching ONE (single) instance of the application. Otherwise I suspect they are actually using Land Enabled MAP (ACAD), and IF that is the case they are using MAP poorly, and should also only NEED one instance of MAP to work on every drawing they have on the server simultaneously.
Not that there may not be an issue with the License Server, it's feature codes, and wether it is releasing the licences correctly. There might be, howeve this seems to be more a problem with PROCESS than the program. I am happy to assist them harness the power of MAP, should they decide to employ the tool properly.