I'm running the lastest PD.02.06
And yes others have also pointed at the cable, well not so much the cable itself the termination on both ends would be the first thing to check. Oh and its be running fine at Gigabit for the past 6 years and only started happening in the last few months.
All the power saving modes are off, that was the first thing I checked.
The Physical Mode is set to auto negotiate for all ports on the switch, looking at the available options you only get auto negotiate, half and full duplex for 10Mb and the same for 100Mb but nothing for 1000Mb
Thanks