When reviewing an Excel spreadsheet, it became apparent that a cell with a RIGHT
function in it was referring to a cell with text in it, in the form of "TEXT  
NUMBER". The RIGHT function was used to extract the NUMBER, and paste that as
the result. Excel recognizes that NUMBER is a number, and pastes it into the
cell as such. OOo only recognizes NUMBER as a textural part of the string, and
pastes it into the cell as text, EVEN THOUGH IT DISPLAYS EXACTLY LIKE A NUMBER!
Of course subsequent references to that cell do not provide the correct answer
if thought of as a number, when it is in fact text.

THIS INCOMPATIBILITY NEARLY COST ME MILLIONS OF DOLLARS!! It was only after
berating an Excel user for stuffing up his spreadsheet was it pointed out to me
that the results I was viewing was not what had been saved in Excel.

I opened the same file in Excel, and verified that it was as they say, and that
OOo had simply failed to recognize the numbers.

I presume LEFT and any other similar functions would perform similarly, and
should also be made compatible.