This has been happening to me since long before the Eco Lifestyle pack or patch. I couldn't travel anywhere without the newest additions to my inventory getting lost in the process, which was especially annoying when I travelled to the Magic Realm to purchase new wands or ingredients, just for them to be gone when my sim returned home. One workaround I found was to drag those items around in the inventory until they lost the star marking them as new, because the bug only seemed to affect newly collected items.
It's gone from my game now, without me installing any mods to stop it, so I assumed the pre-Eco Lifestyle patch would have fixed it rather than causing it in the first place. But if it's happening to you now, try my method described above. It's not an ideal solution, but maybe it will help for the time being.