Delete all the DLC, including your pre order packs in the Game Data(top of the Game section of the XMB) area. DO NOT DELETE SAVED GAME DATA. On PS3 you're forced to delete everything anyway, since it lumps all DLC into one file. Delete the file labeled Fallout: New Vegas DLC.
Go to your Account Management, and click the Transaction Management tab, inside that tab click on Transaction History, then the Download List tab, redownload ONLY OWB, and nothing else.
Start your game, if you managed to make a save outside the Sink in OWB, load up that save and see what you get.
----------------------------------------------------
After doing this and playing, the game runs smooth like it should, no frame rate issues, no frame rate freezing. I can actually play!
Reminder: If you took items from the other DLCs in with you I would recommend reloading your save, before you left to go to the Mojave Drive-In and leave any of that stuff behind, because once you delete those DLCs you cannot use those items.
Once you complete OWB, and you reach the Mojave again, save as soon as you get control of your character, and go download the other DLCs again with the method mentioned above, your other DLC stuff will be returned to you once the other DLC is downloaded again.
EDIT: This may cause you to not be able to level up, I noticed this after playing for a bit. To make sure I didn't mess everything up for good, I reinstalled all the other DLC. OWB is still working fine and I can level up again. Now I'm not 100% sure that the other DLCs are the cause of the frame rate freezes, and drop outs like I originally thought. I would recommend using your own discretion, if you want to level up in OWB you might have to wait for an official fix but that WON'T be happening. If you just want to play OWB I recommend giving what I mentioned above a try, you can always level up once you've returned from OWB, and reinstalled the other DLC data.