Looks Like LJ's being wonky.
Apparantly there's been a glitch in LJ så some people have unfriended people on their flist without wanting to do so. I've seen posts about this around my flist. As far as I can tell I still have everyone up on my flist, but if it looks like I've unfriended you in the last days, then I haven't. Just comment here and I'll add you back.