There's more to experience when you log in!
Sorry I have release build 58, which I think is 19.0
This has been very confusing, but I think I may have solved it.
The first point table I used was not packed (but the version I sent you probably was). I have now tried using the unpacked table and got the wrong values as before, then I packed it, ran again and this time I got correct values!
Perhaps you should add a warning or a routine packing the point table.