From Steven J. Vaughan-Nichols' excellent blog.
" The really big problem in
document formats is what's going to become the next office document
format: Microsoft's proprietary Open XML or OpenOffice's ODF (Open
Document Format). A far more minor but nonetheless very annoying
problem is what do you do about Microsoft's ClearType Collection
typefaces: Calibri, Cambria, Candara, Consolas, Constantia and Corbel?
These were introduced in Office 2007 and Vista. Not only are they new and--need I say it?--proprietary, they aren't simply in addition to Microsoft existing proprietary fonts--Arial, Time New Roman, etc.--they replace them. That means not only are Linux and OpenOffice users stuck with semi-indecipherable text, so are users of older versions of Windows and Microsoft Office.
It's enough to make you think that Microsoft wants to force you to upgrade!
Fortunately, there is a way around the funny font problem."
And of course, there's always the font substitution window. Tools > Options > OpenOffice.org > Fonts.