I am working on a bit of a maze cave, and was merrily doing the joining, when I found one that I could not get to work, even when using line points, so bodged it and moved on. the next one did not work either. This started to make me a little suspicious. In the end, I moved the join commands higher up the file (this was not the first thing I tried by a long way) and both joins then worked. I can find no logic to this, when I move the joins up, others that become get pushed down, still seem to work. The joins are in Reads.th, the thconfig in the reads folder selects only the relevant maps to make it easier to see. Whole dataset is at http://www.cave-registry.org.uk/svn/Burrington/ it is in version 412, the 2 that do not work have comments after them, lines 143 and 144 Running on Debian Therion 5.3.15, I happen to have a windows box for use today, and the same thing happens on that. Adding more joins after and they seem to work. My worry is that moving the ones that do work to a place that they do, might break some other joins, that I cannot find. Andrew