Laptop won’t connect

This one has me perplexed. I’m running NT4.0 under Small Business Server and 3 Kingston 10/100 hubs. I’ve got an HP Omnibook with a Kingston ethernet card that had been connecting and logging on just fine until about 2 weeks ago. It suddenly quit, but there was a linklight. Took the laptop to another location and it connected to the network just fine. Okay, I thought the cable was bad. Had the electrician in to test the line and it tested fine, but he replaced it anyway. Retested and it tested fine. Tried to connect to the network with the laptop again – no go. Brought a desktop in from another office and tried it – connected just fine. Anyone got a clue?