SE4 always uses the first system entry in SystemTypes.txt to fill in rounding errors and such when making maps. I added dummy systems to my FQM files to make it easier to find the various groupings of system types, but it wants to use my dummy "Stock Standard Systems" as an actual system in-game, as it is the first system.

I reported this to MM months ago, but apparently forgot to update FQM, and nobody ever mentioned it.
Solution:
This will NOT affect PBW compatibility in the slightest, as SystemTypes.txt is ONLY read when the map is created, and never again. Delete this entry from your SystemTypes.txt file, in both FQM Standard AND FQM Deluxe:
Name := Stock Standard Systems
Description := ***PLACEHOLDER. Not to be used in-game.***
System Physical Type := Normal
Background Bitmap := Starmap.bmp
Empires Can Start In := FALSE
Mask Background Objs := TRUE
Non-Tiled Center Pic := FALSE
Number of Abilities := 0
WP Stellar Abil Type := Unstable Warp Point
Number of System Objs := 0
[ February 05, 2004, 20:14: Message edited by: Imperator Fyron ]