In a running network, port failures are exceptional.
A port is only faulty when it fails on POST. Undetected failure of in/out circuits is rare.
Always reboot the switches to be certain in case of hardware failures.
Checking your sw-release notes is advisable.
When you are patching a lot, your problems could be caused by ESD. An unused cable is in fact a capacitor and it can accumulate a considerable voltage; enough to blow the life out of a switchport. Take proper ESD countermeasures if this is the case.
Another possibility is that you have switches from a bad production batch. If this the case, a maintenace contract is the solution of choice.
Regards,
Leo
