tabs missing on Excel 2007
 

I reviewed the questions/answers the tab missing but can't find anything
that will work for me. I have 2007. Sometimes the tabs are gone while other
times they are there and I can't figure out what I do to have them invisible.
Any suggestions? It has become a real pain, trying to get them back. I am
useng a sheet that doesn't change, tracks my time so I'm not adding anything
new to it except time in columns.

Thank you.