dell labreastude d600 gigabit adapter disappears in the middel of the day
speaking of rootkits
washingtonpost.com Study of Sony Anti-Piracy Software Triggers Uproar File-Hiding Technique Alarms Security Researchers; Developer Offers...
if i recall correctly, this issue wasn't stated very clearly... and neither has your troubleshooting... you have a laptop that periodically looses network connectivity when docked (you mentioned something about it 'usually happening when in the docking station and that opens the first question as to what port you are using... dock, built in, pc card??). you said you have tried other docks. you said you would try other ports on your network hub-switch. i suggest you continue to eliminate variables such are the premise cabling (run a temporary network cable to another office or direct to the network hub-switch if you have to). change out the patch cables between the hub-switch and the patch panel, and then wall jack and the computer. if you have other identical dell model laptop then swap the hard disks and see if the problem follow the old laptop or stays with the software build-hard disk that is in the 'new' laptop. it sounds like this is either a cabling issue (not dells problem) or a docking station connector issue (laptop motherboard issue). hard to diagnose. but if you swap the hard drive with another identical unit and the problem follows the original laptop then you know that the issue is with the laptop (and not the software build).