After a thoroughly depressing experience installing F:NV Ultimate Edition over the top of a previous install of just plain F:NV (I had to delete the whole F:NV install to get it to work properly) I now find the software will not disable the DLCs when told to.

Steps:

I launch Steam; Click on Library; Click on Fallout: New Vegas; Click on Play; Click on Data Files.

This opens up the list of available DLCs etc. I have unchecked all but the base FalloutNV.esm. "Load Loose Files" is unchecked. I then click on "OK".

Disappointingly, all the DLCs still appear in the "DLC" menu when the game launches; and as soon as I load a saved game I am immediately flooded with all the DLC alerts.

A solution, please?

--Windows 7 Professional 64-Bit; Mac Pro 2010; no F:NV mods installed; system rebooted after install of F:NV Ultimate Edition.

Just delete the .NAM files from your data directory, there's one for each DLC. Without them you wont be forced to load the DLCs but you can still enable the DLCs the usual way by checking them.