Formulas no longer working

All of a sudden all my formulas stopped working. My macros are functioning but thats it. A simple one like =F13 doesn't work. I have a copy of the file on my laptop which works great. If I clear all formatting for the 2 cells it will work the first time only. I am confused and disappointed. Any suggestions? Its excel on a work server so a reinstall is out.

EDIT: I have tried checked the automatic tick under the calculations tab as mentioned in other posts. I have also tried to format both as general. WHen I change the value in one cell such as B1 it will not put the same value into A1 if A1 contains =B1
It will however change once I close and reopen. I cannot keep doing that to make it work. HELP!!!!!