I'm not sure of all the doctors that aren't working, but of the doctors I've discovered, and used, only one works... that Being the Doctor in Megaton. The rest, so far, don't heal me, though they still charge me. (The other doctors I've used are from the Underworld, and Tenpenny Tower. I couldn't find the Doc in Rivet when I was there... he wouldn't come out of his room...)
I looked through FNVEdit, and the only thing that each of the doctors have in common appears to be the Fallout3.esm. Most of them also have a connection to the TaleofTwoWastelands.esm, and TTW Redesigned, which isn't surprising. I don't know if this is helpful or not, but I figured I'd share it.
LOAD ORDER:
[collapsed title=Hidden text] [X] FalloutNV.esm
[X] DeadMoney.esm
[X] HonestHearts.esm
[X] OldWorldBlues.esm
[X] LonesomeRoad.esm
[X] GunRunnersArsenal.esm
[X] ClassicPack.esm
[X] MercenaryPack.esm
[X] TribalPack.esm
[X] CaravanPack.esm
[X] Fallout3.esm
[X] Anchorage.esm
[X] ThePitt.esm
[X] BrokenSteel.esm
[X] PointLookout.esm
[X] Zeta.esm
[X] TaleOfTwoWastelands.esm
[X] Advanced Recon Tech.esm
[X] TTWFixes.esm
[X] Interior Lighting Overhaul - Core.esm
[X] streetlights.esm
[X] TTW Redesigned.esm
[X] AWorldOfPain(Preview).esm
[X] AWorldOfPainFO3.esm
[X] Detect Traps.esm
[X] Interior Lighting Overhaul - L38PS.esm
[X] oHUD.esm
[X] Project Nevada - Core.esm
[X] Project Nevada - Equipment.esm
[X] Project Nevada - Rebalance.esp
[X] Project Nevada - Cyberware.esp
[X] Project Nevada - Extra Options.esm
[X] Interior Lighting Overhaul - Ultimate Edition.esp
[X] Advanced Recon Gear.esp
[X] Advanced Recon Gear - Project Nevada.esp
[X] Advanced Recon Tech.esp
[X] Advanced Recon Tech - Detect Traps.esp
[X] AWOPLowLootGeneral.esp
[X] WeaponModsExpanded.esp
[X] AWOP-LowNPCS.esp
[X] project_nevada_-_ttw.esp
[X] Alternative Repairing.esp
[X] Alternative Repairing - Breakdown Item Icons.esp
[X] Alternative Repairing - Tale of Two Wastelands.esp
[X] ammoingredientsloot.esp
[X] Armored Duster.esp
[X] EVE FNV - ALL DLC.esp
[X] AWOP FO3 - AWOPNV - WMX - EVE.esp
[X] AWOPLowRobots.esp
[X] CASM with MCM.esp
[X] DarNifiedUINV.esp
[X] Detect Traps - DLC.esp
[X] Detect Traps - Perk.esp
[X] Detect Traps - Traponator 4000.esp
[X] DYNAVISION 3.esp
[X] Easy Hacking.esp
[X] Easy Unlocking.esp
[X] FlashlightNVSE.esp
[ ] Guaranteed Pick Pocket.esp
[X] ILO - PipBoy Light.esp
[X] JIP Companions Command & Control.esp
[X] karmafix.esp
[X] Project Nevada - Rebalance Complete.esp
[X] PNxEO MCMScriptFixes.esp
[X] Project Nevada - Cyberware Additions.esp
[X] Project Nevada - WMX.esp
[X] Regulator Armor.esp
[X] RWD-TTW[Merged].esp
[X] The Mod Configuration Menu.esp
[X] The Weapon Mod Menu.esp
[X] TTW - Fellout.esp
[X] TTW Book of Steel.esp
[X] TTW EVE + TTW Redesigned.esp
[X] TTW_Bobbleheads.esp
[X] TTW_SpeechChecks.esp
[X] TTW_Reputation.esp
[X] EVE - TTW Reputations.esp
[X] TTW_MoreCookingItems.esp
[X] ILO - Tale of Two Wastelands.esp
[X] Project Nevada - All DLC.esp
[X] TTW - Realistic Interior Lighting.esp
[X] More Perks.esp
[X] Alternative Repairing - Ultimate Edition.esp
[X] ILO - GS Shack.esp
[X] Delay DLC - TTW.esp
[X] TTW - Realistic Interior Lighting - BS.esp
[X] TTW Perk Overhaul.esp
[X] TTW - Realistic Interior Lighting - OA.esp
[X] TTW - Realistic Interior Lighting - PL.esp
[X] TTW Advanced Recon.esp
[X] TTW_AnchorageCustomization.esp
[X] TTW Anchorage Customization - Speech Checks.esp
[X] TTW_StartupMenu.esp
[X] TTW_OutcastTrading.esp
[X] TTW Patch_Outcast Tading_BoS.esp
[X] TTW_Difficult_Journey.esp
[ ] TTW_NoKarmaDCFollowers.esp
[X] TTW_StashPackOptions.esp
[X] TTW_SuperMutantRebalance.esp
[X] TTW_XPReduction.esp
[X] WMX-ArenovalisTextures.esp
[X] WMX-EVE.esp
[X] Merged Patch TTW.esp [/collapsed]