The initial report was misleading. The others who have seen this (up to 7 now in approx 300 systems in my supported group of laptop users) all were supplied with Swell Fatitude* D600's. It appears now that the NIC chipset on the MB has a weakness that may cause a failure. This has only occured with system over 3 years old. this is, coincidentally, the term of the standard warrenty Big surprise, we paid for the extended and have an extra year of onsite service.
Swell* field tech support for us has been very good. Something to keep in mind even though It cannot be compared to retail owner's support in any way.
When I have my users call Swell*, I do a conferance call more often than not and explain what I have already done to troubleshoot. Usually they put in the call to send a tech before the end of our phone call.
Ain't troubleshooting fun?
FYI, I've also seen the hard drive and LCD screen on this model fail much too often.
*Names changed to protect the guilty.