Unwanted bold font in Word 2007 Equation

[lzhongsh]

Hi:

I have a problem with Word 2007 Equation. I wrote some equations in my
word document and next time I opened the document, some of the
equations were changed to bold font, while others remained unbold. I
changed those bold equations back to unbold, saved the document and
exit. Next time I opened the document, those equations were changed to
bold font again. I cannot figure out what is wrong with my document.

Please help me fix this problem.

Thanks!