We have a server running Windows Server 2008 Standard attached to a KVM (it runs our Polaris ILS system). For a reason as yet undiscovered by me, the keyboard sporadically cuts out. The mouse still works during these disruptions and both it & the keyboard work normally with the other servers on the KVM.
We've attempted to plug the server into another port on the KVM and attach a keyboard & mouse to it directly. No luck with either of those potential fixes. The keyboard will pick up after a reboot, but, inevitably, it will stop working again. I see no pattern in the amount of time it works before failing.