I recently switched to Lion and have noticed a new problem: at what seems to be random intervals, I lose the ability to save my TextEdit files, and to open others.

The saving problems start when I get a notice saying the file cannot autosave. If I try to save the file myself, I get the following notice: "The document “lawexam2” could not be saved." If the document does not yet have a name, I don't get any notice at all, but the document does not save.

My problem is basically the same as in this thread. Documents I opened ten minutes ago suddenly give me the message "The document “lawexam2” could not be opened. You don’t have permission. To view or change permissions, select the item in the Finder and choose File > Get Info." Of course, in Get Info it says I have read and write permission- I'm the administrator account.

Attempted solutions:
1. Rebooting: The issues can be temporarily fixed by rebooting, but it's a giant pain to copy everything into google docs and reboot my computer five times a day.
2: Repairing permissions: I've tried repairing permissions through disk utility and through the password reset utility you get to through rebooting with command+R.

Other (possibly) Relevant info:
-When I checked "get info" on an unsave-able file this last time, I noticed that while my account said *I* had read and write permission on the file, between my account name and "everyone," there was a grayed-out icon and the name "Fetching..." which never fetched.
-When I used terminal to check my file permissions (thanks to IvanLasston on the linked thread), it said "-rw-r--r--@ 1 Alexis 501 6662 May 8 16:35 /Users/Alexis/Desktop/lawexam2.rtf" and I know it should be "rw-rw-rw"
-I am the administrator and only account on the computer, except for the generic guest account. There was a previous account on the computer, but I deleted it before switching to Lion. Is that relevant?
-This is a Macbook Air running Lion 10.7.3.
-"lawexam2" is my "History of Law" exam-- I'm a history student, not a lawyer! My PhD quals are all due Friday, so being able to open and save lots of documents is pretty crucial right now. Please help!