Question about Netgear GS105GE

I recently realised that my internet connection is unstable. A ping test showed that about 20% of my outgoing packets were lost (packet loss). To analyse the error, I tried various measures and finally disconnected the switch from the network - and lo and behold, the packet loss had disappeared. The switch is about 4 years old. Is it normal for a switch to cause such problems over time? Is there a way to fix the problem or should I replace it?