Recently my cable for my xbox 360 internet got wrecked and now I have to go out and buy a wireless adapter. As I went to go play Fallout 3 it told me that some things (the dlc) were missing and that certain things might be removed from the game. When I went to my quests all the DLC quests were removed so my question is, Will my DLC quests come back on this character when I get online again?

Probably not since they've been disabled for that save. Your only hope is to load an older save from before you lost your cable.

If thats the case then its not really too big of a deal, thanks for the input.