Yes, OpenOffice www.openoffice.org have some limitation and problem. but what is best alternative ? I think not Koffice or others, which is not even an office suite.
I think instead of reinventing the wheel, of creating another open source office alternative and wasting time, better to make openoffice better, which will be start very soon (version 2).
Read Draft of Product Concept Document
I hope other open source developer which want to make office alternative (including Koffice), can jump to openoffice project, better to help openoffice and make it better.
Meanwhile the current version 1.1 which will be final very soon, which is better than Star Office 6.0, it have many thing to be improved before 2.0 is coming.