QUOTE(mizer666 @ Jan 28 2009, 03:39 PM)

Ok so in short - if i buy the GTA Lost And Damned card to download the expansion for it, get the HDD and put it into "clean" console, log into live using the clean console, download the DLC, then remove the HDD and put it back into my "no so clean" console, then i won`t be able to play the Lost And Damned ?
Correct. The only way to do it is if your modded console is not banned. You then download the DLC using that one instead so in the even of a ban you'll still be able to use it. Of course, signing onto Xbox Live on the unmodded one will give you access to the content there too, but only you will be able to use it (useful to know if more than one person uses the 360).
You can actually take this one step further. If your modded console is ever banned, you can use the MS License transfer tool and transfer all DLC from the banned one to the good one. You then just need to re-download it from your account history and it will then be tied to that console too. Yes, because the modded one is banned it'll be the same story there as well. End result: both consoles will be able to use the content for any user without being connected to Xbox Live.