I have been using bb5's for about 10 months and today the rear caliper (?) failed. It seems as if the spring inside is the problem. The caliper doesn't return to the correct position. Any ideas?
Thanks.

This, or similar, issue was just gone through. Here ya go:

https://www.bikeforums.net/bicycle-mechanics/479518-my-avid-bb7-blew-up.html

Thankyou,
I'll go see my lbs on Monday and see if he can help me out.

Well the problem was a broken spring. Very disappointing concidering the age of them (less than 12 months)
It's too much of a pain to chase a claim (ie. wear and tear cough-cough bullsh1t).
This is on a street bike not a mountain bike, and my braking style is not aggressive, but how does one argue that...impossible.
The LBS was extremely helpful and we came to an agreement over a replacement, so I'm happy.

I fixed mine but I got a replacement for 40.00 thats only twice the price of new pads that I needed anyway.

Unfortunately in Japan, the discounted price for a bb5 is 9975 yen. Pads here (genuine) are 2700 yen a set. I purchased BBB replacement pads for 1700 yen a set and are wonderful.
Also it appears, Avid spare parts are difficult to get here.

BB5 costs $106.00 USD in Japan? It's only $35 (2007 model) or $47 (2008 model) and for $3 more you can upgrade to BB7's ($50 2007 model):

https://www.pricepoint.com/thumb/3-Pa.../Disc-True.htm

Yes they are a rediculous price. Probably why you don't see so many bikes around here with them. The only reason why I have / had them is because the bike came with them standard. My replacement was a BB7, I expect the same cheap crap (my opinion) as the BB5. I paid 1000 yen for the BB7 as my LBS had it lying around and I only had 1000 yen in my wallet.

BB7 is as good as it gets for a mechanical disc brake system. Adjustments are a lot easier than the BB5. The 2008 model of BB7 is lighter.

I've never heard a bad word about the BB7s. I have them on an off road race bike and they see some pretty nasty conditions. They have been flawless.