Obvious mega fix for that: copy your SpringData string into weblobby's Settings -> Spring Home.The SpringData dir should be used to listen to what the user wants, not telling him what the lobby wants. I already stopped using weblobby because of this, because each time I use it I have to go back and reconfigure my SpringData dir variable to read from multiple places.
There are exactly three mentions of SpringData in SWL source:
-> SpringData is set by weblobby verbatim from your springHome setting.~/Programs/qtswl$ grep --exclude-dir="*.svn" -sirn "springdata" ./
./site/lwidgets/Lobby.js:289: this.getUnitsync(version).setSpringConfigString('SpringData', this.springHome );
./site/lwidgets/Lobby.js:547: this.unitSyncs[version].setSpringConfigString('SpringData', this.springHome );
And i think this is exactly how it should be between lobby and engine.
Multi-lobby single-engine installs are probably something only a spring developer should have in the future where games go on Steam and package themselves.