Here's my situation: Before Lion, I had SL on both my iMac and MBP. I used my iMac as the host for internet sharing and connected to the wifi with my MBP. Once I upgraded to Lion, everything was still working as it should. Then my wife went out of town and took the iMac with her. When I hooked my MBP up to ethernet, I could not get a connection. When I opened Network Diagnostics, I couldn't even choose 'Ethernet'. It was grayed out and defaulted to wifi even though i had wifi turned off. I could only choose wifi or 'other'. I power cycled my modem, hoping it was just an IP issue, but that didn't help. I restarted my computer and that seemed to fix it until my battery died the following day because I guess I forgot to plug it back in. So I plugged it back in and turned on the computer, and now I'm having that same problem as before. It's as if my computer doesn't realize the ethernet cable is plugged in. So, I think to myself, this is BS, but I guess I gotta restart it again. Well that didn't help. I've restarted my modem and computer so many times and nothing works. I'm currently on my neighbor's wifi. I know it's not a bad ethernet cable because it was just working earlier today, and my modem is showing an active link, but in Network Preferences and Network Diagnostics, it's acting like it's not plugged in, but it is. Is anyone else having this issue?? Does anyone have a solution for me? Thanks!