The Management Service allows you to do some auditing. There is a whole tab for this in the QlikView Management Console. See QMC->System->Setup->QlikView Management Service->Auditing.
However, it seems that the switch to enable QMS auditing has been permanently disabled. No worries, though. You can switch it back on by tweaking a configuration file in C:\Program Files\QlikView\Management Service. For more details, read the help page in the Auditing tab.