When I attempt to "save as", or Ctrl-S, certain of my Excel 97
workbooks, this results in a new sheet tab named Module 12 appearing.
If I right click on this tab and select delete, the tab dissappears
and I can continue to work in that workbook. Any other action locks up
the Excel program and I have to Ctrl-Alt-Del and End Task, lose
whatever I've done.

This is quit vexing and I would be most appreciative of any and all
advice and help!