General :: Locked Files On HFS - Home Partition Shared Between OSX

I dual boot into Arch Linux and OS X 10.6 on my MacBook pro. I synced my UID between both OSes and created an HFS partition (with no journaling) to use as a shared home/Users partition. For the most part it works just as I'd expect, but sometimes when I'm booted into OS X certain files are "locked" (when I get info on a particular file the "Locked" box is checked under the "General" pane. I can resolve the issue by manually unchecking the box) and/or I get "Operation not permitted" when I try deleting or chmod'ing a file. In both cases I don't see anything out of the ordinary on the permission bits displayed with ls -l, except for a trailing '@' character in the position where the sticky bit would normally occur:

This '@' character shows up on ALL normal files, so doesn't seem to be linked to the locked/operation not permission situation.

On the Linux side of things I never have permission problems. To the best of my limited knowledge and experience with ACLs I've not found any ACLs on any of the files in question.

For what it's worth, I do most of my file editing using emacs (Aquamacs in OSX), is it possible it is setting weird permission bits?

What is the "locked" setting that OS X uses and does it have a permission bit equivalent (so at the very least I could recursively unlock all files in my home directory from the terminal) why might some, but not other files get "locked" when booting into OS X what is the meaning of the '@' character?