OK, the first question I've got to ask is: have the got the Game Of The Year version of Dawn Of War? Because if you have ... that's your answer right there. In order to annoy everyone and be very helpful, Relic have patched that version of the game to Patch 1.4. Wow! That's very good, I hear you cry. Wrong! Because most of the Mods only run with Patch 1.3. Updating the Mods to accept Patch 1.4 has been apparently difficult - don't ask me why.
Therefore, the Game Of The Year version will not run 90% of the Mods and this is why they are not activating in the Game Manager. It took me a lot of time and effort to work this out myself, but that's the reason. If you want to play the Mods, then you'll have to buy the original version of the game, available through Ebay, and then install the patches to Patch 1.3, which will involve installing the patches one-by-one: ie: Patch 1.01 -> Patch 1.1, Patch 1.1 -> Patch 1.2, Patch 1.2 -> Patch 1.3, all available at
www.dowfiles.com.
Of course, if this isn't the case, then you will have to provide more details before I can help you. Good luck!
- Rogue Trader (Hereticus Diabolus)