Getting error while connecting to network

Hi,
I have one PC which reliably connects to the internet via the network, but does not reliably connect to the network itself. IPCONFIG /RELEASE, then /RENEW and /ALL indicate that the setup is correct.
The cable disconnected icon never appears, but I tried a different cable anyway. I found I could ping the server using its IP Address, but not its name. It seems like a software problem, but apparently the user gets under the desk and wiggles the cable, and then he can connect to the network .
Can anybody give a solution .
Thanks friends.
