copy & paste formula between spreadsheets - not working
 

Normally if I copy and paste a cell or range of cells from one spreadsheet to
another, I get the cell(s) value to paste across; or if the source cell
contains a formula, I get the formula to paste across. I also get the option
to Paste Special and can chose values, formulas, formats, etc. etc.

I have one spreadsheet that will only copy a cell's value to the destination
spreadsheet (even if the source cell contains a formula). If I select paste
special, instead of the usual dialog box - formulas, values, formats, etc.
etc. - I get what looks like an object paste box with none of the options
that I want or expect. instead I see options for pasting a picture, bitmap,
XL object, XL 8.0 Format, etc. - whatever I chose I get an object or similar
pasted with the source cell value - no sign of the formulae.

I think there's a switch set in the source spreadsheet that is protecting
the cell data or making Excel think the entire spreadsheet is an object, or
whatever. I've made sure the cells are unlocked, the sheet is not protected
- what should I try next?

I've got 1800 rows of killer-complicated formulae and retyping them or
copying off the formula bar one at a time (yes that works!) is enough to
drive me to drink. Thanks.
Glibby