Used GECK with FO3 for a long time without any issues.. however I'm facing a weird problem that I can't figure out with the NV GECK. First off, I'm unable to fill in the Author/Comment section of my mod(s).. Tells me something along the lines of "Access denied"
Whatever.. moved on, as thats not a priority.. However:

After saving the mod in GECK and closing out and going over to the NV launcher->Data files: My mod(s) aren't listed, nor are they showing up in the data folder directory...but can see the files there if i use "open" within GECK.

So yeah, Unable to select mods to load via nv-launcher (It detects the DLC pack (Mercenary))

Any help would be appreciated, have quite a large mod in mind.. but this proves a large hurdle in that process.

Sounds like you're running into a permissions issue with Vista/7 virtualizing that directory into ProgramData or VirtualStore, though this shouldn't happen if you have a sane Steam install.

Yeah.. it's got me completely lost. This is the error I get, Any ideas to fix this?

I downloaded someone else's basic house mod and deleted all their content, I'm currently able to work from scratch/edit/save/load from that base file. ...Still annoying, but atleast found a way around this stupid permission error.

Did you install in Program Files?

Vista or Windows 7

Right click on the Fallout New Vegas folder and select properties. Uncheck Read Only and go into advanced. Look for "user/your name" and check full control.
It's a little confusing but you will find it. This will give permission for Geck to write to that folder and any under it. This won't change any other folders in programs.

Should solve your problem, did for me.

Or you can reinstall Fallout to somewhere outside of Program Files.

FONV gets installed into your Steam directory, and Steam automatically sets proper permissions on its own directory: there should be no problem with this.

Do you have vista? Right click and open as administrator the geck

Stupid question.

Have you rebooted? Something might have left a stale handle open. "process explorer" can help you nail that down and close it if you don't want to reboot.