wp to wp import/export – missing

Hi. I’ve two wordpress blogs and would like to combine blog 2 into blog 1. I have about 183 posts in blog 2. however, when i try to import the xml file into blog 1, only 99 posts were showing? i’m just wondering what happen to the other half of the posts? what do i have to do to make sure that i can import all the posts into blog 1? please advise.