office 2007 excell losing info

Morning all im wondering if anybody could help me with an excell 07 issue im having.

when i enter information into excell i save and exit but when i reopen the document it seems to lose the information not just a few cells ive looked at the new updates for office but i dont find anything that helps with the specific issue
is there anybody that has the same problem and if so how did you remedy it as our sister office in zambia is having the same isssue in a different file.