I couldn't find the original thread, so I'll start a new one.
One of my local group wrecked a pawl/ratchet part of the mechanism on a new 105 shifter. The shifter wasn't repairable, but now you can get little internals modules for about $60 that replace everything in an STI shifter except for the hoods and lever - i.e, all the fine mechanicals.
Anyway these are apparently quite easy to install and it's considerably cheaper than a new set of STI shifters.
