if i understood the first post correctly it was not just about the 'breaking' of parts but also the timing aspect that it happens right when you are about to finish anyway.
things break from time to time that just happens if you are bashing your rigs like they 'deserve' it. as for the timing aspect my feeling is that this may be due to two connecting factors. first off you start to do the more crazy stuff not right in the beginning when you just put all your stuff into place and got ready to run but wait until you have several battries through. and secondly maybe its just the concentration that fades away after some hours (and e.g. some beers later). at least for me its quite like that. the sun is setting ... and you have this one battery left and the ramp is still there....just one more time... full speed - jump .... crash. there you go and have something to fix again.
byer
rhylsadar