i'd like to throw some thoughts into this discussion regarding USB, LCC, the key and licenses showing up leaving aside licenses (left wing) and content (right wing) showing within VI/VE ...
i noticed on a not so old PC that a certain USB port does occasionally loose contact - this was an electrical/mechanical issue and wobbling the pluged-in device restored the connection. not a solution but the reason for the issue was found.
in another case it turned up the chip sitting behind the USB port has been electrically damaged and actually 2 USB ports have been affected and no relible communication has been possible over this ports.
a third problem - often ocurring if one has more than one type of controller in a computer - is an updated driver which fails to communicate to a certain chip (VIA chips are the most affected models here)
related but based on different reasons is the USB 1.0, 1.1, 2.0 protocol combined with improper loaded drivers where evrything appears correct, but communication fails due to a failed *handshake*.´furthermore there are 2 types of USB 2.0 devices, which are unfortunately not labeled differently, though the older one is rarely seen.
this type of problem often happens if a USB 2.0 hub sits in front of a USB 1.1 port - again the (protocol-)handshake can fail, though everything appears to be ok. also the powered hub a such can die (happened to me past week - everything looks fine but occasionally no communication)
the third group of problems is related to voltage and current. each type of USB port should provide at least 100 mA with 5V (+/- 5%) but this pecification is not always met and some devices take more current than allowd so lowering current below the allowed tolerance and causing other devices to no longer work properly.
eg. USB connectors on apple keyboards are not recommended for attaching keys, this often is causing communication problems.
the fourth group of problems relates to OS X as such, especially the 10.5.6 version where changes to the USB protocol have been made (to prevent jail breaks for the iPhone) what apperently caused also problems with certain devices.
so if a dongle is not recognized remove all other devices (harddisks, webcams, audio devices, phones, ect) and retry resp. plug in directly to the computer and consider problem group 1 or 2 might apply ...
the licenses as such do not disappear, they might temporarily not show up. even if a dongle itself really *dies* we can help you out with replacement licenses - everything else is a more or less simple communication issue.
christian