How does Mass Effect 2's DLC affect saved games?

All,



I recently played through Mass Effect 2 several times over the course of the past few months and finally got wireless access for my XBOX 360. I was thinking about getting the Downloadable Content (DLC), but wasn't sure if it would mess up my saved games. What I'd like to know is:



1. Does the DLC work on saved games? For example, if I've completed the majority of the missions (including the Suicide Mission), will getting the DLC for Zaeed and Katsumi mean that I can just pick them up before completing any remaining side missions?



2. On two of my six playthroughs I used a cheat to create infinite skill points. While I've read that the DLC includes a patch to fix this, will this mean that these previously saved characters will suddenly be de-powered? I only ask because I read an article stating that this cheat may affect the importing of characters into ME3 as well (i.e. if characters have mismatched skill points).



Bottom line: I've enjoyed playing the mass effect series but don't want to jeopardize my existing saves. I did my best to play through with the intent of importing each version of the character into the final installment.



Any advice, tips, or anecdotal experience will be very helpful.



Best,



TKO_12How does Mass Effect 2's DLC affect saved games?
Try to backup the saved game files first.