I screwed up Steam and it wiped all my games. So I re-installed Steam last night and re-downloaded all my games.

Now, when I go to play FO:NV after installing all my mods again, it only acknowledges certain mods while ignoring others. Plus, it only acknowledges the Dead Money DLC and ignore Honest Hearts and Old World Blues....

Anyone have any ideas what is going on???

Quick check, have you:
-Validated the game cache through steam
-run BOSS on your load, then rearranged unrecognized mods
-made a Merge/Bash patch

Also, a load order report would be helpful.

Its also best to always test the base game first, before (if you have the room) copying it off to a backup folder so it will remain untouched before adding in mods that could mindscrew Steam and/or New Vegas into thinking its borked.

I told Steam to delete content and re-installed and now it is recognizing all mods - not sure what happened the first time. Thank you for the responses!

J