i've been having similar problems since i got apx "n".
i've been on the phone with apple most of the week. they have a group dedicated to "n" only, trying to figure out what is wrong with them.
finally got the "n" to work, but now my express is crap. i joined the network like they said, but itunes won't stream properly and i keep losing network signal to the "n". i keep getting pageouts on my browsers, my signal fluctuates (it's only 6' from my macbook, itunes crashes and then i lose signal. i spent 3 hrs on the phone with them today and about that yesterday. tonight they gave me a case number and said to call back tomorrow when a FRESH group of "n"-only techs will be in.
i'm beginning to think it's the extreme "n" card in the macbook. didn't have the problem until i got the extreme "n" base station and enabled the mb to "n".
the emac still works wonderfully during all this -- on the same network -- no loss of signal etc. and plays itunes fine through the express. the mb worked fine also until i "n" enabled it.
i get 2 secs of music and then 3 minutes of nothing, 5 minutes of music and then a couple clipouts of a sec or so each, then nothing for 20 more minutes.
yesterday i was only having the problem when visualizer was on. today it's all the time. when the music is off, so is my browser, or is extremely slow.
but the emac takes a lickin' and keeps on tickin'.
oh, and the extreme "n" base station doesn't completely run a printer right. it will print, but you lose all the utility functions like ink levels and ability to clean nozzles. applecare said you have to plug your printer into the computer's usb port to use those functions -- you can't make it work through the apx.
call back tomorrow and talk a few more hours. at first i thought it was my normal pebkac, but it's not THIS TIME.
