Hi, all!
I have the same problem here, although not with an AE; rather, it is a regular AirPort card and AEB. I installed Tiger on my PowerBook and my 800-MHz G3 iBook. The PB is connecting and working smashingly, while the iBook does exactly as the OP described: It won't even see the network let alone connect; it will connect full strength when within a foot of the AEB, but then decrease rapidly as it is moved from it; and sporadically it will connect, but as soon as I move the cursor, the connection vanishes.
Personally, I think that it is a problem with Tiger. My card is seated perfectly. No other applications were installed or uninstalled. And everything worked perfectly until I did the achive & install of Tiger. As I stated, my PowerBook (which also is running Tiger) is fine, which leads me to believe that it is not a problem with the AEB.
Finally, my iBook is not detecting the wireless network where I work. Before Tiger, it did.
I spoke with an APple Tech today, but had to disengage from the call before we got into anything other than shutting down and rebooting the network. I still have an open ticket and will followup on it ASAP. If a solution presents itself that is other than a bug fix from "the mothership", then I'll post it here.
This also does not appear to be an isolated issue as there are a couple of threads on Apple's Discussion Boards about this. Believe me, it's not a case of an unseated AirPort card or a misconfigured setting.
Other than this issue, Tiger is awesome! Heck! I even like the new mail.
But, if anyone has a similar issue or knows how to resolve this, please chime in here. Thanks!
Have fun... Tony.