One thing I forgot about, that could have caused this DLC status reset... a few days ago there was blackout while I was playing D2:ED. When the power came back on (10 minutes later) the Xbox seemed fine (unfortunately it was plugged into the surge protection side of the UPS, rather than the battery powered outlets), and I played again for awhile before I saved, and noticed the save was listed at the bottom of the list, since the date had been reset to November, 2005. I changed the date and started playing again, and all seemed fine. I'm pretty sure I sold the Blood Echelon set relatively soon after downloading it, either immediately or the next time I started running out of inventory room. If I hung onto it until getting the battle tower, maybe that is why my two oldest saves contain DLC with the stats unfixed, while later saves do not.
In the 'more questions' topic, I said I couldn't check the equipped set bonuses, but I don't recall way back then well enough to know if the saves did not contain the set then, if I just didn't check the right saves for it, or if I assumed I sold it right away, so didn't look for it.
Hopefully someone else with DLC can provide some feedback on their experience, and my random stats can be written off as a glitch (or confirmed, but that doesn't seem likely).
