Difference between Excel for Mac and Windows

[gonj...@gmail.com]

I have develop an application that throws an excel spreadsheet however I have notice difference in "interpretation" between mac and Windows version of Excel, for example,

:alignment => {
:vertical => :top,
:wrap_text => true,
:horizontal => :left
}

Excel for Mac shows align left and wrap_text fine, however Windows Excel doesn't wrap up... is it because interpretation of ECMA?
Anyone Else facing this?