Office 2007 on a Windows 7 PC. A user has an intermittent problem where when she copies a cell with a formula in it, clipboard picks it up as text. Typically, if one pastes a copied cell with a formula it also puts the formula in the cell. Not always with this one. Likewise the drag feature where one can grab the lower right corner of a cell and drag it down to past the contents of that cell into the cells below. Doesn't work sometimes. Similarly large numbers (13 digits) copied paste to a cell in text and are jacked up.
We've tried closing Excel and reopening. Rebooting. Even a complete uninstall and reinstall of Office. Not helped.
Any ideas?

I suspect the cells are defined as "Text". A cell defined as text will not apply any Excel's own formatting/definition and is only what is entered. If you copy a "text" cell the destination cell is "text" as well. Try redefining the source and destination cells as "general", "date", "number", etc. before using the copy/paste feature.