K The world does revolve around Apple so, of course, a wireless connection just has to be an Apple branded one. I am no genius but I did spend a ton of my own time tearing out my hair while I tried to connect to a linksys and a dlink wireless router with a mac and pcs. I got the same message. I have seen dozens and dozens of threads like yours and mine in this forum. They never seem to get solved. Eventually, the questioner just gives up and the thread dies. The only things you seem not to have done is to play around with the encryption types. Some people will have luck with wep others with wpa etc. etc. I have concluded that the underlying problem is that Apple is likely using the exact white papers standard for each encryption scheme while the Pc  gear makers all cut corners and have drivers that are just good enough for pcs. Before I give my answer, though, I should mention that the 802.11d standard is a global standard that allows a laptop to travel to other countries that have different wireless restrictions than ours and that can be tweaked to comply with different countries wireless eccentricities. So if this lappy has been globe trotting it could have been set for, say Hungary in some weird way and that could be the problem. If not, this is my best advice. You have already spent more of your valuable time on this than it is worth. Just buy an Apple Airport Extreme base station for your home and/or office. Your connection problems will vanish and your pc's will connect with no problems either. Just divide how much you make per hour at your normal job by the cost of a new base station. You may already be in the red with time spent already. So just buy one and move on.Your macs and pc/s will both play nice.

While I agree with pheidius - insofar as the Apple Airport Extreme is VERY compatible with Windows and OSX and works reliably - going out and spending almost twice the price for an Apple branded router when you already have a well-known branded router is not always an option.

The problem, in 90% of cases, does seem to come down to the encryption methods implemented by different branded routers .. and Apple not liking some of the implementations of WEP created by Netgear etc.

This is the sequence that I try when setting up Macs with Netgear/Belkin/Buffalo routers.
1. Disable ALL encryption (WEP/WPA etc.) on the wireless network and using a wireless scanner such as iStumbler (on the Mac or a PC equivalent) check that the wireless channel is one that does not confilct with any other networks in the area.

2. If that works .. then you can step into encryption options
a) the most reliable but not always practical is to block all computers and allow by MAC address of the wireless card.  This nearly always work with all Apples .. but is not viable if the network will have lots of changing users. Plus with MAC spoofing it is possible to bypass the securiy.
b) The WEP encryption standard is the most abused by all the manufacturers.  Apples DO NOT like many of the WEP formats used by Netgear, Belkin etc.  The 2 tips I can offer are
- Stick to the precise standard of 10 character Hexadecimal key for 64 bit WEP, and a 26 character Hexadecimal key for 128 bit WEP.  Although some brands let you use ASCII WEP keys .. avoid this.
http://www.practicallynetworked.com/support/mixed_wep.htm
- On certain routers place a Hash (#) in front of the WEP key
- Note WEP is notoriously easy to crack just Google it and you'll find loads of sites.

3. WPA is a much better standard and Apples like this better although older Apples airport cards do not have WPA support. Again, try and adhere to the specific standards of the type of passphrase.  Don't use real words, avoid special characters and use at least 8 or 9 characters.
http://blogs.zdnet.com/Ou/?p=127

Sorry, I was trying to include all information but I clearly forgot to state that I have made all of these networks 'open' when trying to connect and still no joy...

I don't have any networks which use WEP, i normally use MAC Filtering as you highlight above or WPA if it must be a passkey...

THanks for your help guys, I'm not a MAC user but I am very experienced with PC's, office networking and wireless technologies and this issue has just confirmed what I knew about MACS the whole time.

If its owner wasn't such an important client I never would have agreed to even look at the problem...but now I have accepted I'm determined to fix it!

I have an Airport extreme base station but he travels ALOT and needs it in other locations too!

He has another Macbook PRO 15" which he bought at the same time which works perfectly with all wireless networks so I don't believe it's the compatibility of the card...I reckon it's something to do with the configuration that's embedded on it...

I will try removing the card and then reseating it again, see if i can get it to recognise it as a new piece of hardware...

Might be time for an Apple Repair .. if it is under warranty

So has he traveled abroad with this machine. As I said this card version in an international one. Maybe someone fixed it for him in some country he was in and he did not understand  the significance. I was definiltly looking for the lack of connection with no encryption though. That does point at the hardware.  You may want to read up on the d issue first though. The following is ultra dense:
http://www.patentstorm.us/patents/7103314-description.html

Ok thanks for that...I'll read through it.

So, last point: is there any way of resetting the card back to factory default setting? Or do I have to wipe and reinstall the whole macbook?

After this I'll close the question. THanks!

hehe that what I meant when I said dense. I started to wade through that but it was the wrong time of the day. I will  try again later.