OS X V10.7 Lion :: "Mail Can't Open Because You Don't Have The Necessary Permissions To Change The Folder Where It Saves Information"

I am no longer able to open Mail. I get the message: "Mail can't open because you don't have the necessary permissions to change the folder where it saves information"  It then goes on to tell me where mail stores information and to go to that folder and use the Get Info window to change the privileges to Read and Write (which they already were). I authenticate, change them to Read and then back to Read and Write, click the lock and try again. Same result. I tried to take a screen shot of that window and got this message: "Your screen shot can't be saved. You don't have permission to save files in the location wherescreen shots are stored." Last night I tried to take a screen shot and got the same message. I repaired permissions in Disk Utility and there were thousands of permissions repaired.