So I searched around here and the wiki and couldn't find this particular problem.
Long story short, I severely overestimated myself during a siege. While I managed to bbisect the invading force before taking them on, my dwarves... weren't quite ready. I slaughtered what I caught, but at a cost. I went from 17 Military Dwarves to 5. These 5 are now total badasses, but still. 12 dwarves slain.
Anyways, my problem is that one of the killed dwarves had been hospitalized before, and had a thread and cloth on him [suture/bandage], and he died inside a door way. I thought nothing of it, and dumped the two items with the rest of his stuff. After my dwarves cleared the hallway... the thread and cloth was still there. I checked to see if they were forbidden, or somehow owned, but they aren't... I forbid them, waited a minute, then unforbid them... nothing... Then I removed the dump and instead was going to allow them to be placed in a stockpile. A season later they're still there. I know they're accessible because I just cleared out everything else in the hallway, and even cleaned it. This wouldn't be that big of a problem, 'cept it's keeping my door open.
Also; I don't know if this is relevant, but the items don't seem to have an icon. The door isn't there, obviously because it's open, but the space is empty, instead of a thread/cloth icon.
Nevermind. Closing the game out and then reopening it fixed it for some reason. Odd.