Nintendo always have excellent customers service. MS on the other hands....
Anyway, I have some DLC that I purchased on my first 360 and I have to returned it to get the price cut (this was back around the pre-Holo price cut. (Target refuse to match the new price claiming that it is not a sale and a price "drop" thus they do not honor it and only way to get it at the new price I was pretty much told to return it and buy another one, I was so annoy so I returned it and took my money to Best Buy).
In anycase, a few games that I got on there (Pac-man CE, Worms and some Forza DLC) no longer work when I am off-line. Most of the times I am on live anyway but there was a time where I have to move the console where I have no Live (the TV died) and those DLC items no longer work. I called MS they promise to fix it but they never did. I called them back a few times but get the usual we have to escalate this matter crap. (To their credit they did try to contact me back couple of times) I redownload everything but it still did not work. Forza DLC for some reason was fix (I think this was done via Turn 10 patch because I remember seeing a lot of complain on the forum about this issue.
May be I should try it now and see if may be MS finally got around to retie it. Last time I talk to MS rep I was told since this was not a "repair" console ie , I exchanged my console through retail MS do not retie the DRM to new unit.
