I also just issued a build that might have a fix for the cache failure, you have reported earlier. I happened to reproduce the kind of problem locally on my machine and I kept the logs and the cache. And replaying the logs (+libfaketime) was successful in reproducing the SERVFAILS
You just caught me in my spamming mood - since the service company keep replacing parts at random on the order of manufacturer's Czech branch, I sent emails to them, then bugged them on twitter and finally on Facebook too :). I am probably skipping G+.
I know that feeling.. lenovo failed to repair my notebook for 3 weeks, 5 attempts.. ket it at their monkey repair facility for days without updating, screwed up delivery addresses, ... no support from their side :/