Yeah, I've wondered the same thing but the DA 7900 is only 2 years old. Seems like it's hardly long enough to go bad. The thing that stands out to me most is the lack of a ferrule in the brifters. I think my first order of business from here will be to change cables and include the ferrules as required, process of elimination. If I put fresh cables in her, including the appropriate ferrules, and I still have the issue, then I can start looking more intensely at the RD itself. It will be a few days before I can make the swap but I'll report back my findings.