I have no issues with any dlc but I own each one. So either your install needs to be checked, if using steam, or just reinstalled. The only other ideas that come to mind are a part of the current game become dependent on older dlcs which you may not own or game patches which fix a dlc you do not own created in error. The game dev's patches do not treat dlcs as individual addition to an existing game but as part of the current game itself.
*coughs* Dodgy rips *coughs*
I buy games these days, but at the time I didn't have easy access to Steam, etc, and ripped this. When running the game, it doesn't always recognise the DLC. Sometimes it does, sometimes not so much. I suspect it's something not quite right with the files, etc.
Kinda serves me right.