Hi, I used the MacRumors Buyer's Guide for several months to find the best time to buy a MacBook. I'd never had a Mac before and found it to be so valuable. I hope someone in the forum can be as helpful as the site has been. Yesterday I bought a new MacBook Pro 13" and as a store option the RAM was doubled to 4GB. Everything has worked well so far, in both OS X and Windows XP through Boot Camp, except for either OS accessing the LAN cable on my home ADSL. Both my portable modem (EMobile network in Japan) and the wireless seem to work with no issue, and both OS will recognize the ethernet port. I'm concerned that perhaps the ethernet adapter was modified when the store installed the memory. I can remove the ethernet cable from one computer (where it works without any settings changes on my Windows notebook) and plug the same cable into the MacBook and it will not be recognized. The Mac OS error is that no cable is inserted. However, as it's my first Mac, I didn't know if perhaps some new settings are required to make things work smoothly. Is there any DNS settings etc. that must be set for it to connect? Also is there some kind of connection diagnostic that will specify the location of the error in the machine? I'd like to exhaust any option before shipping this back to the store to be repaired or replaced. Thanks in advance for anyone who might be able to help. After years of cheap Windows laptops I decided to splurge a little to get something of quality I could use for years... I hope to be able to use it at all!