Are you using the function with the correct variable types - short or float?
short iCombExpfloat fSneakAttenExpset iCombExp to GetGamesetting iCombatExplodePartChanceset fSneakAttenExp to GetGamesetting fSneakDistanceAttenuationExponent
The only new functions that deal with settings are FOSE functions:
short iXPRewardKillNPCVeryEasyGSfloat fDifficultyMultiplierGSset iXPRewardKillNPCVeryEasyGS to GetNumericGameSetting iXPRewardKillNPCVeryEasyset fDifficultyMultiplierGS to GetNumericGameSetting fDiffMultXPN