WiFi Trouble

I have a Macbook with Tiger.

Worked great for the first year I had it.
Last spring it started to drop it's wifi connection now and then.
I was able to turn the airport off/on to remedy the problem.

Recently it's started dropping the connection and the only way to restore it is a complete reboot.

Thinking it was software, I did a fresh install without saving info/settings of OS-X Tiger. This also failed to remedy the problem.

Given that my home network hasn't changed (and other devices work great on it), and a fresh install of OS-X doesn't help, it must be a hardware issue right?

I'm going to drag it into an apple store this afternoon to see if those people have any ideas.

Next school semester starts on Monday... I'm hoping it will be resolved soon!

My Macbook has the same trouble at school, work, my girlfriend's parents, and a couple friends houses as well.

I brought it into an Apple store this past weekend, but unfortunately I couldn't get it to drop it's connection there. Of course I only had it on for about 10 minutes. Sometimes I'll have a great connection for an hour, other times it's only 5 minutes.

They did quote me $300 for a full diagnosis and replacement of parts (along with them taking my laptop for a few weeks). This seemed outrageous to me. They also won't sell me any parts for my laptop which is lame.

I absolutely love the synergy of my Laptop, iPhone, and Shuffle - but I'm at a teetering point. I'm going with another homebuilt PC for my next desktop this year (due to a lack of an apple product that fulfills my needs at the right price level), and with my Macbook having these troubles my next laptop next year might be from a knock-off brand like Sager or Prostar. I was thinking about stretching for a Mac Pro, but with unresolved issues with my Macbook my confidence in the "Just Works" mentality of Apple products and their premium prices (which up until now have been justified in my mind) have been shaken.