KSP Crashes on fourth stage of specific rocket - things are starting to get really weird

[SpaceLaunchSystem]

KSP: Mac 0.90 32bit

Problem Story: I'm building a statin in Munar orbit. I have the first module there and am trying to launch my favorite lander/interplanetary shuttle (I call her the Phoenix) plus a docking hub to connect to the Station. Here's where it gets really, really weird: When I try to stage the fourth stage, the game never fails to crash. It doesn't happen for any other rocket; just this one.

Mods Installed:

000_ToolbarActiveTextureManagement
AerojetKerbodyne
AnimatedDecouplers
BahaSP
CrossFeedEnabler
Firespitter
HabitatPack
JSI
KAX
Kerbaltek
MechJeb2
MechJeb2 Embedded by Dennis6492
Modulefixer.dll
ModuleManager.2.5.13.dll
ModuleManager.ConfigCache
ModuleManager.ConfigSHA
NearFutureConstruction
NearFutureElectrical
NearFutureProps
NearFuturePropulsion
NearFutureSolar
NearFutureSpacecraft
ProceduralDynamics
Pteron
R&SCapsuledyne
README.md
RealChute
SDHI
SmokeScreen
SpaceY-Lifters
ToadicusTools
toolbar-settings.dat
TundraExploration
TweakableEverything
TweakScale
Virgin Kalactic

Reproduction steps:

Copy my rocket, launch it and try to stage the fourth stage. For me, at least, it will crash the game no matter how hard I cross my fingers.

Player.log

Edited April 11, 2015 by SpaceLaunchSystem