Now, since you mention the Nexus, this means you use Mods. It is a mod related issue for you, not a game related issue as this is not a problem for anyone else. Find the offending mod and remove it or update it or fix it.
Um, that's interesting logic, but no. It has nothing to do with mods. The only one I currently use in Skyrim is to fix the UI. Sorry.
In response to the other suggestions - yeah, if I run far enough away I can get out of range of whatever it is, but the problem is that I can't bring the bedroll with me. It's still back at the camp where I'm trying to sleep and not being allowed to.
I've circled around the spot a dozen times and there's nothing there except one rabbit, which for some unknown evil-rabbit reason keeps darting back TOWARDS the damn camp everytime I try to scare it off into another cell. Either the rabbit is considered an enemy, or there's something else nasty in the area that I'm completely missing. Whatever it is, it almost has to be a non-hostile because otherwise it would have shown itself and attacked me by now, right?
All I can guess is that the area being checked for enemies is larger than I realize, and that's why I came here asking if there might be a way to shrink it. If not, oh well. I'll abandon the idea of sleeping at this particular camp and move on. I just figured I'd ask.
EDIT: Ah-freakin'-ha! Figured it out. The distance WAS significantly greater than I'd thought. I hadn't originally checked a nearby lake for enemies because it seemed too far away for any aquatic hostiles to matter, but when I expanded my circling search and still couldn't find anything, I figured it almost had to be the lake at that point and I was right. It turned out there was an angry slaughterfish lurking in the water and once I'd killed it, I was able to finally sleep all the way back at the camp. I still wish there were a way to shrink that distance... seriously, I really don't think it's dangerous for my character to camp near a lake because there might be pointy-toothed fish in the water, lol.