<mfrac> elements not showing up properly in netscape

All,

 

I am trying to use MathML in our application. I tried the xslt approach
using pmathml.xsl, 

<mfrac> elements rendered fine in IE and it got kind of superscripted in
netscape and mozilla.

Could anyone please let me know why it is so? I have attached the sample
file that I've used for testing.

 

Thanks in advance.

Bagath