This is typical windows problem.. most MS wireless drivers do not do roaming well. I suspect it is now Apple's turn as they continually swap hardware wireless cards used in their routers and laptops. Getting roaming to work is often difficult.
Did you by any chance have this Air running say Lion .. where it was ok and upgrade to ML and then the problem started. Upgrade installs of OS IMHO are never a great idea.. I would encourage a clean install always.. and whatever updates are offered to see if the driver issue can be eliminated.
I do not think there are any controls for this on the routers.. so no changes you make will be that useful.. but as an old computer man.. wireless and AEBS names should be short, no spaces, pure alphanumeric. When you do extension of wireless, lock wireless channels. And use wpa2 personal only. I am not convinced this will fix anything.. but lets say it is the right way to do it.
I got a Gen 5 airport extreme to test wireless.. and found it no different to Time Capsule of previous generation. So this new high power wireless made no discernable difference. In fact in my house where networking equipment is in a front bottom room.. at the back of the house upstairs.. I get wireless from my G Thomson wireless modem router.. and zippo from every TC I have tested as well as the AEBS. Since I repair TC, I can have up to 4 of them running at a time.. and not one has signal up to the extreme end of the house. On slow adsl the G wireless is perfectly fine for internet.
Are there other routers I should look at such as Cisco that would perform over distance better? I'm literally 20ft if I were to go straight through the walls and about 35ft in total how I'd walk it where there are no doors.
Thanks and good thinking.
Wireless goes in dead straight line.. Tx station to Rx station.. so draw a line through all the walls, floor, furniture, meat and water bags, and worst of all metal.. mirrors are metal.. pipes and wires and reflective insulation.. all reflect signal.. solid materials absorb it. The more solid the material, bricks, concrete, the more signal is absorbed .. the greater the thickness of the material the more is absorbed.. thin sheetrock (plasterboard we call it).. and wood, is much better than more solid construction.. so wifi is opposite of huff and puff of the big bad wolf. A house of straw or sticks would be perfect. Wire mesh reinforced concrete that is damp the worst.. (water absorbs the microwaves.. ever wonder why microwave ovens use 2.4ghz). It has metal reflector plus solid material that is thick plus water.
The better routers should make 20' in normal house.. although there is still no guarantee. ie Through the damp concrete wall with the mirror behind it.
This chart is set for the worst location in testing of a large range of wireless router.
http://www.smallnetbuilder.com/lanwan/router-charts/bar/58-2_4-ghz-dn?see=P_F
Pick one near the top and you will get the best signal you can in domestic equipment. I have a ubiquiti AP-N router.. stands head and shoulders better than the AEBS. It is EOL model but ubiquiti are more towards pro although their prices are pretty ok.
Also moving things around can help.. keep wireless routers up high.. most of us have furniture at floor to waist level.. put wireless routers above that. Point the things at the device.. the antenna in the TC and AEBS are around the sides.. nothing much comes out top or bottom.. nothing out the back where the wires plug in.. think of the front led as a laser.. aim it at the receiver. Position it to go through as little material as possible.
Then go an buy high power wireless router.. you will find the difference amazing.
