Thanks to Duoas for solving a bit of a problem (btw I carelessly posted a support question in News & Discussion, sorry folks). I had a giant domino rally set up for a short animation which had to be three seconds long, but the simulation ran to 9000 frames. Duoas pointed me towards the ‘Map New’ feature, which I didn’t even know was there (and probably wouldn’t have known what to do with even if I had!). I set the Map New value to 10 meaning the whole thing ran at a tenth of the speed and hey presto. The result, for your perusal, is here:
I tried to follow another suggestion to shrink the keys using the NLA window but I ended up with all sorts of IPO glitches. Fallen dominos would start twitching around and other anomalies. The other option, to render all 9000 frames and delete the ones I didn’t need, was unworkable because Yafray was taking a good ten minutes per frame and this needed to be done by tomorrow morning!