If you've got the Madd Dogg Glitch where he jumps off the roof and dies before CJ can do anything about it then you can repair your save with hmvartak's Online Gitch Repair Tool
. Just select the Pedestrians Riot option (default), upload your save to the site, and download the repaired file.
This glitch is caused by using the Pedestrian Attack Each Other cheat (Pedestrian Riot on PS2). Once you save the glitch is stuck in you saved game.
If this is not the problem you are having then please explain more clearly. You might want to check out the useful links in the Mission Help forum to learn how to upload you save if you want someone to help complete the mission for you, or just take a closer look at your save.