Hi Stem,
Wow, thanks for this bug report. That has apparently been a fault since this particular tool was introduced in L3DT v2.6 in August of 2008. Since no-one else reported this fault in the past 3.5 years, one is inclined to conclude 'level at' is not terribly popular with users. Good to know.
Anyway, the scaling factor that you found to be 10x is actually the horizontal scale; Sapphire internally uses a coordinate system scaled down by the horizontal scale such that adjacent pixels are 1 unit apart. In this case I forgot to take this scaling into account when setting the heights of the 'level at' tool start and end points.
The fix is done, and will be wrapped into the next developmental build. If you need the fix immediately, the updated plugin is available here:
http://www.bundysoft.com/L3DT/downloads/plugins/bin/Sapphire-bin.zipThanks again!
Regards,
Aaron.