I have this same problem, but I was unable to fix it with what you described.  My situation happened when I went in multi-user mode and then right back to single user mode after figuring out that wouldn't solve our company's problem.  When I went back to single user mode, this problem started happening.  It has been happening for about a week, and temporarily one day everything worked again, but now it is back to not letting me resize columns.  Also, I can't drill down into all of the numbers - only some of the numbers (like only expenses and not revenue numbers - super weird).  If anyone finds a fix, please let me know!