[Xenomorph]

Here's what I have in each entry that Chem_SmallPoisonFieldWeaponGamma shows up in.

In the weapon.ini

;Weapon Chem_SmallPoisonFieldWeaponGamma
   ;  PrimaryDamage = 2.5			
   ;  PrimaryDamageRadius = 7.5	 
   ;  AttackRange = 15.0
   ;  MinimumAttackRange = 10.0
   ;  DamageType = POISON
   ;  DeathType = POISONED_GAMMA
 ; WeaponSpeed = 600					 ; dist/sec 
   ;
   ;  FireFX = GC_Chem_WeaponFX_SmallPoisonFieldWeaponGamma ; This ;FxList is marked UseCallersRadius,
   ;  ; so the damage range can be tweaked and it will change the effect's ;radius too
   
    ; RadiusDamageAffects = ALLIES ENEMIES NEUTRALS NOT_AIRBORNE
  ; DelayBetweenShots = 500			 ; time between shots, msec
 ;End

In ChemicalGeneral.ini

Object Chem_PoisonFieldGammaSmall
   
     ; *** ART Parameters ***
     Draw = W3DModelDraw ModuleTag_01
   	DefaultConditionState
   	  Model = NONE
   	End
     End
   
     ; ***DESIGN parameters ***
     EditorSorting = SYSTEM
     KindOf = IMMOBILE CLEANUP_HAZARD STICK_TO_TERRAIN_SLOPE INERT NO_COLLIDE
     ArmorSet
   	Conditions	  = None
   	Armor		   = HazardousMaterialArmor
     End
   
     ; ***AUDIO parameters ***
     SoundAmbient	  = AnthraxPoolAmbientLoop
   
   
     ; *** ENGINEERING Parameters ***
     Body = ActiveBody ModuleTag_02
   	MaxHealth		= 120.0
   	InitialHealth	= 120.0
     End
     Behavior = FireWeaponUpdate ModuleTag_03
   	Weapon = SmallPoisonFieldWeaponUpgraded;Chem_SmallPoisonFieldWeaponGamma
     End
   
     Behavior = LifetimeUpdate ModuleTag_04
   	MinLifetime = 10000
   	MaxLifetime = 10000
     End
     
     Behavior = FireWeaponUpdate ModuleTag_05
 	Weapon = HazardFieldCoreWeapon ; Prevents stacking of fields with a small blast of cleaning at the core at startup
     End
   
     Behavior = DestroyDie ModuleTag_06
     End
   
     Behavior = FXListDie ModuleTag_07
   	DeathFX = FX_AnthraxPoolDie
     End
     
     Geometry			= CYLINDER
     GeometryMajorRadius = 4.0
     GeometryHeight	  = 1.0
     GeometryIsSmall	 = No
     
   End

And in GC_Chem_GLASystem.ini

Object GC_Chem_PoisonFieldGammaSmall
   
     ; *** ART Parameters ***
     Draw = W3DModelDraw ModuleTag_01
   	DefaultConditionState
   	  Model = NONE
   	End
     End
   
     ; ***DESIGN parameters ***
     EditorSorting = SYSTEM
     KindOf = IMMOBILE CLEANUP_HAZARD STICK_TO_TERRAIN_SLOPE INERT NO_COLLIDE
     ArmorSet
   	Conditions	  = None
   	Armor		   = HazardousMaterialArmor
     End
   
     ; ***AUDIO parameters ***
     SoundAmbient	  = AnthraxPoolAmbientLoop
   
   
     ; *** ENGINEERING Parameters ***
     Body = ActiveBody ModuleTag_02
   	MaxHealth		= 120.0
   	InitialHealth	= 120.0
     End
     Behavior = FireWeaponUpdate ModuleTag_03
   	Weapon = SmallPoisonFieldWeaponUpgraded;Chem_SmallPoisonFieldWeaponGamma
     End
   
     Behavior = LifetimeUpdate ModuleTag_04
   	MinLifetime = 10000
   	MaxLifetime = 10000
     End
     
     Behavior = FireWeaponUpdate ModuleTag_05
 	Weapon = HazardFieldCoreWeapon ; Prevents stacking of fields with a small blast of cleaning at the core at startup
     End
   
     Behavior = DestroyDie ModuleTag_06
     End
   
     Behavior = FXListDie ModuleTag_07
   	DeathFX = FX_AnthraxPoolDie
     End
     
     Geometry			= CYLINDER
     GeometryMajorRadius = 4.0
     GeometryHeight	  = 1.0
     GeometryIsSmall	 = No
     
   End

A thorough search yielded no other instances of that weapon, yet the problem persists.