Does anyone out there know why my new airport express will not communicate with any computer further than 10 metres from it??

I have set up one iMac (using OS 10.5.2) inside one metre and it works fine. My second iMac which sits in the room next door only sees the express on an intermittent basis.

Is this a problem that can be fixed or do I throw away the express??

assuming you've already tried changing channels...

I had major issues with a distance LESS than 10 metres. Then I moved house. Furniture rearranged differently. Distance greater too. No longer clear line of sight as well. And now the computers/AEBS see each other very well.

There was a chunky metallic object (kind of like a table) within 5 metres of the AEBS in the old house which now is outside on a patio. I think that was the difference. I had tried moving it in the old house without any improvement. But sending it way way away to the patio was the big difference.

I suspect that some object in your house may be playing havoc with the signal, not necessarily the wall.

Though someone on these forums would know more than me about good and bad wall materials.

Fiddling with the channels should sort it out, if not, it could be faulty. Mine has been working flawlessly for 2 years, and I can even access it from the Pool Bar-B-Q area three floors down and 20 metres away.

Is your express 'n' or 'g'?

My 'g' that I've had for under a year was intermittent as well.

I recently got an airport extreme 'N' and a couple of new 'n' expresses and the streaming of audio around the house has improved immeasurably since.

I have 2 expresses ('N'- but the whole network is running at 'g' as my macbookpro is 'g' only) that are at least 10 and 20 metres from the extreme and using the remote app on the iphone has been excellent. Connects and streams almost instantly. I've only had a drop out twice in the month since this setup.

Prior I had a belkin wireless router ('g') and one express('g) and this was very flakey.

Acton, consistent with my previous post and to sort out for sure your appalling signal strength/reliability:

Is there internal wall insulation, ESPECIALLY the type with foil backing. Ouch! Internal metal supports, frames or metallic paint? Pipes running up the wall, very old cables inside the wall?

Do you have an old microwave oven in the house or a microwave oven nearby? Do you have a cordless phone in the house? A baby monitor? A bluetooth device like a game console pad or an earpiece or a mobile trying to synch? Are you in a commercial area? Near a computer shop? If you live in a block of units then there's a good chance these days that someone is using the same channel, even if your Mac doesn't report that the channel is being used. A nearby garage door opener being used? Is there a kiddie magnetic whiteboard nearby?

Is the AE near ANY potential source of RF noise like ANY device with an external power supply.

If it's a concrete wall then just forget it. If basically Gyrock then no problems.

Can your iMacs see other networks? If so, what channel are they using? Are any of these hotspots as they could be using signal amplifiers?

At a place where I worked the security system together with the refrigerator and microwaves and the roofing materials (single storey prefab on an industrial site) and the metal walls played havoc with the newfangled 802.11 network. We spent ages positioning things to try to get reliable throughput. But that's an extreme example.

Moving to 802.11n on 5GHz gets away from electrical appliance problems and most neighbours would not be using 5GHz. But it also means that structural problems with the building you are in will be worsened.

As I said above, moving house and rearranging the furniture solved 95% of my mysterious instances of my airport just losing connection with my Macs. Not asking you to move house though...

Acton - I've had probs with APX since upgrading to the new 'n' model.

machines see it ok but if another notebook goes online I get intermittent signal, slow internet unless I go plug in with cable to the ethernet port.

got bumped by a Compaq pc laptop yesterday - for goodness' sake!

tried everything I know - even to the point of calling Apple.
tech support walked me thru a few things I'd already tried and then they agreed, scratching their heads too, that the APX could be faulty and have given me a job # to go to the nearest Apple service centre (45 mns drive away) and have it checked out.
because Apple centre probably won't look at it for a few days, I've held off until I can be bothered - until then I soldier on.

I wonder if others have has similar problems?
the older 'g' model APX worked faultlessly for years, hosting up to 5 machines without blinking

As above.. make sure there is nothing in the wall or near by that is interfering with the signal.

Do you have an iPhone connecting to it? If you've got the AEX set to 'n' and your iPhone or Touch connects to it it'll drag the whole network back to 'g'...

Otherwise if you still have problems, perhaps a re-set of the AEX would be in order?

(more than likely it's placement issues though)..