HELP PLEASE: Blinking '98 Avalon Airbag light

Hi folks,

my wife and I own a '98 Avalon with about 175k miles, still runs great and is in really good condition, but we have an issue.

my wife is the primary driver of this car, and also very short. I don't drive it much, but I am fairly tall. when she drives, the drivers seat is all the way forward, and when I drive, the seat is all the way back. (this will be relevant shortly)

about a month ago, the Airbag light on her dashboard started occasionally coming on, we took it to our mechanic who read the codes and tried to diagnose it but couldn't find the problem. we started paying more attention to what happened before the light would come on, and it seemed to happen more often when I would drive than when she would drive, but if I was driving, I could move the seat up one notch, turned the car off and back on again, and the light would stop...

over the month though, it's spent progressively more time on, and now it's totally on and nothing we can do will get it to go off (short of removing the fuse...)

our mechanic says that he's unable to trouble shoot it any further without taking the drivers seat out of the car, and can't give us an estimate on how much time it will take to find the problem and fix it... so for now we're trying to do some research on our own.

has anyone had a similar problem, or know of a recall that effects '98 Avalon airbags? any ideas what the faulty component might be?

Thanks