be careful when converting from iso-8859-1 to utf-8.
even if you explicitly specify the character encoding of a page as iso-8859-1(via headers and strict xml defs), windows 2000 will ignore that and interpret it as whatever character set it has natively installed.
for example, i wrote char #128 into a page, with char encoding iso-8859-1, and it displayed in internet explorer (& mozilla) as a euro symbol.
it should have displayed a box, denoting that char #128 is undefined in iso-8859-1. The problem was it was displaying in "Windows: western europe" (my native character set).
this led to confusion when i tried to convert this euro to UTF-8 via mb_convert_encoding()
IE displays UTF-8 correctly- and because PHP correctly converted #128 into a box in UTF-8, IE would show a box.
so all i saw was mb_convert_encoding() converting a euro symbol into a box. It took me a long time to figure out what was going on.