All dongle protection systems since pretty much ever have had issues with the computer's time. I once spent a huge amount of time trying to work out why a FlexLM license to MotionBuilder wouldn't work. Turns out a directory on the root of one of my hard drives was time stamped 10 years in the future (I think I was testing something). But as a result the FlexLM driver (which uses a dongle but of a different design than iLok) decided my permanent license was no good. Changing the timestamp on the directory fixed it. Now it shouldn't have mattered, my license didn't have a time element but the software cared about the time it thought it was being correct and so failed.