If you use OpenOffices Formula-Feature, you can choose three alignments: left, centered, right. But if you chose left, not only the text ist aligned left but also the numerator of fractions ist aligned left.
This is a little example. If you use longer equations it looks even worse:
aligned to left
cheesehead(Brainstorm admin)
wrote on the 19 May 09 at 02:22
Improper mathematical formula formatting is a bug. Please check Ubuntu's bug tracker at launchpad.net (and OpenOffice's bug tracker) to see if it has already been reported. If not, please file bug reports with enough detail to be reproduced and triaged.