I Downloaded through my PSN account, all the free Little Big Planet DLC and the 2.20 update(i think). I use a .ISO file and run it through the default Inferno UMD ISO Mount. noDRM is enabed in the Recovery Menu/Advanced/noDRM Engine. None of the DLC loads but shows that i have it on the games menu, What could be the issue?

This is a PSP 1001 with CIPL 6.60 PRO CFW.

Is the DLC the same region as the game ? UMD ISO MOUNT is used ONLY for UMD VIDEOS. Not for games.

Yes the Game is US and the DLC was downloaded on a US PSP from a US Server. I physically purchased the DLC and used the ISO for the game.

You need to patch the iso with ISO TOOL for the PSN patch to take effect. That might be the reason why your DLC is not working properly. Did you install the DLC properly using Media Go ? Simply copying the .pkg files wont work. If you're using 6.60 and you properly purchased and installed the patch - you don't need noDRM to use the DLC. the problem lies elsewhere.