This might not be so slight for some people, but for me I'm not particularly worried because I've already got platinum and I never use daedric artifacts (except for black star) anyways. It might already be a known issue too so oh well.

I completed the quest to get the ebony blade and I thought it looked cool so I figured I'd stick it in my weapon rack in Whiterun until I felt like using it. Fast forward awhile and I completed the TG questline. I went to go store my ebony blade in the chest so I could put the nightingale blade and chillrend in the weapon rack and I found that my ebony blade had disappeared. I know I didn't complete it on another save whilst drinking because it was in my journal as completed (I checked) and I never sell unique stuff. Maybe Farengar broke into my house and stole it back, maybe Lydia is planning to kill me in my sleep with it, who knows.

Anyways, on to Hjerim. I completed Blood on the Ice bugged like everyone else and ended up buying this house after completing the Stormcloak questline. The option to "clean up the murderer's mess" never showed up and I was ok with that because the room where your enchanter and alchemy lab are look awesome with human remains and blood splattered everywhere. It fit my evil character. I decided to decorate my house with my spoils of war, the various swords that Ulfric had given me over the course of events. Leaving and returning at a later point empties your home of the weapon racks and dagger display cases and such. In short, it completely resets your home as if you'd never entered. I think Blood on the Ice ends up bugging the house. I found it a little annoying at the time so I stayed away from that house afterwards.

Sorry, I'm not sure what your request is, but I also lost something, early on. I attempted to put the Ghostblade on the rack in the bedroom in Solitude, but it immediately disappeared. I never found it. I hope it reappears after the patch but I doubt it.

The Ghostblade and Ebony Blade both have known issues when displaying them on weapon racks, both of them can just randomly dissappear. It is a known issue, but whether they have fixed it for the upcoming patch, who knows? I would rather they fix the lag and the Dragon Infusion Perk bug.

My topic is old in internet time, but a couple days ago I was standing there looking and my ebony blade did not disappear. It had simply fallen out of the weapon rack and had camoflaged itself by laying parallel to the shelf just to the right of the weapon rack in breezehome. I feel pretty stupid now, but everything else I posted was more of a heads up to people and not asking for help.