Opening a project gives error (mac)

I have my project saved to "Users/Shared/Unity/SpaceShip" with SpaceShip being the project folder. I created The project from an account on this iMac, and everything works fine from that account. However, when i try to open the project from a different account, I get these wonderfull messages:

Creating directory
Creating directory Temp failed. Please ensure there is enough disk space and you have permissions setup correctly.

I Know that the problem isn't permissions, because both accounts are administrator. Clicking Try Again merely brings the error back around for another tour of the desktop. I dont want to click quit, so i click cancel. Then the errors brother comes for a visit.

Opening file failed
Opening file Temp/UnityLockfile failed because the file or directory does not exist

Once again, Try again sets the merry go round spinning. Force quit sounds remarkably similar to quit, so cancel gets the prize. After cancel is clicked, i have no more visitors, either error's or humans. Putting the mouse over the unity bar at the top is forbidden, as the computer eats the mouse and replaces it with that spinny-wheel-of-death that every mac user has learned to dread.

So here's the questions:
1. How do I fix this?
2. Is there a space that is actually shared between all accounts?
3. Do you like my humor? (lol)

Have fun,
-Navi