Locked Files in OS X Lion Oct 18, 11, 5:30 p.m.

Over the past couple of weeks or so a problem has developed on my Mac with saving files, usually with an accompanying error something like this: "Could not save as “fileName.ext” because the file is locked or you do not have the necessary access privileges." I've had this happen in Photoshop and Illustrator, as well as in Safari when trying to download a PDF off of my job's server. It continues even if I manually unlock the file on my hard drive. Anyone else experience this? I don't have Time Machine running, but just in case, I disabled its file locking feature. It didn't help. Any insight would really be appreciated.