If the import source is FusionBB and there is actual HTML in the post_raw_body field of the posts table, the importer will crash and with it Apache.
The importer must check the post_raw_body for any presence of HTML and remove it. The particular field should contain only markup code and text.
Example: one of the records had the following in the post_raw_body field:
<img src="http://www.domain.com/forum/images/graemlins/wink.gif">
and it should be:
:wink:
Removing the HTML allows the importer to work just fine.