Can’t load intra sites before re-enabling LAN connection

Interesting situation; we have bunch of Sharepoint intra sites hosted on local server within our domain. Usually after client computer restart these sites can’t be accessed and IE throws the Page cannot be displayed error. Going into network connections, disabling and enabling the LAN connection does the trick, connection repair won’t suffice.

The intra sites don’t reside in the Domain Controller. Both servers running DC and Windows Sharepoint Services are Windows Server 2003’s. Ideas, anyone? A possible DNS issue?

Cheers,
Mikko