70% signal. 2 inch gap

I have a Macbook aluminum and I get 70% signal max when my Macbook is seriously sitting right next to the router. And yet my wireless disconnects and reconnects constantly? When I am in my room I get only about 30-40%. I get disconnected from Adium and cant load web pages. Does any one have any clue how to fix this?

Things I have done:
-Changed my channel multiple times. (according to Air Radar there are channels 1 6 and 10 in use on other networks. Am running channel 3 at the moment.)
-Had comcast replace my router
-Had a comcast tech guy come out and some how change something on my network. (didn't help)
-check my cordless phone, its a 5.8ghz model.
-Scream and throw things (haha jk )

But seriously any help would be appreciated!

As a test, take your MacBook someplace that offers free wireless. Starbucks, a public library, etc. Check the signal strength. Or, if you know someone with a wireless network, take your MacBook there and check out the signal strength. If the same problem occurs, make an appointment with Apple to take the machine on in and have them look at it.

Regards.

Its only a week old. Do you think there is something wrong with it?

is it your wireless router or your modem? if its your modem, i have time warner cable and have a similar problem, (ie internet cutting out and not great signal) and it turns out it is actually a problem with the cold weather causing problems in the cable lines outside.