For the first few hours after having powered up the PC, the (Gigabit) network adapter is working OK. But by midday it starts to repeatedly disconnect / reconnect from the network. I can physically see the light on the switch flick off/on. Whilst surfing the internet it is not too noticeable - just a moments delay - but an alert pops up in the system tray that a network cable has been unplugged and then a moment later I get another popup saying it has connected. It is then only a few minutes (sometimes shorter) before it disconnects / reconnects again. As you might imagine, this is painful on the LAN.
When connected there are are no errors and all works OK. It's either on or off.
I have tried different cables and reseating the PCI network card, but the problem returned a few hours later.
The 10/100 built-in network adapter works OK, so it would certainly seem to be something to do with the network card or connection with the motherboard?
The network card is over 2 years old.
So, my question... is this a symptom of a failing network card? Or possibly something more serious with the motherboard?! Or should I just have another go at sticking the card in the machine?