I had 24 60% dagger attack scrolls in my shop, unfortunately i didn't know that my USE inv was full. So when i clicked on my items to drag them out into my inv, it said at the bottom right corner (where it says how much exp you've gained, how many mesos you've picked up etc) "Your Inv is full", but i lost the scrolls because there was no where for them in my inv, they weren't dropped nor were they in frederick. Tested the same thing with an ETC item and i lost the etc item as well.
http://royals.ms/forum/showthread.php?t=3116 Apparently you don't learn from your mistakes, which makes more work for the GMs. L2commonsense.
Full use inventory I had 2 60% int for earring scrolls that I got from Singapore Gacha and I tried to take them out of my shop but my inventory was full so I guess they disapeared. Also, I d/ced right after exiting my shop(I don't know if that was related)