In order to provide some help it would be great to know the following:
1. What kind of wireless router are you using? Model -Rev. Number - Make- Firmware Version - FCCID
2. What kind of wireless security are you using?
3. Are you having issues on 2.4 or 5 Ghz or both?
4. When you say your Mac drops its connection, does the AirPort icon go grey or does it stay black?
I can't give you much of the information now because I am at work.
I am using a Motorola Surfboard Modem (can't remember model #)
WEP security
Bars(airport icon) stay black
I will be running my new i7 next to my girlfriends MacBook and my older unibody MBP. I will go to the same sites at the same time. The bars stay full. The older MBP and MacBook go to every site quickly and easily. They stay logged into Wow... While my new i7 can't stay connected to WoW, can't go to many of the same sites as the others. It drops constantly! The other computers work as they should. My new i7 doesn't. I have had Apple laptops for years and have never have this happen. Hell, even my Powerbook titanium G4 667 works with my wireless.