[@netweb Keymaster 13 years ago]

The best idea I have at the moment would be for you to post on http://pastebin.com or http://gist.github.com an excerpt of your phpBB table with a couple of entries either site of this mysterious ‘5 month mark’

Fire up phpMyAdmin and open your phpBB database:

Run the following query substituting > 5 & < 15 values with appropriate values from a couple of rows that shows what data IS being imported and also what is NOT.

SELECT * 
FROM  phpbb_topics 
LEFT JOIN  phpbb_posts ON phpbb_topics.topic_first_post_id = phpbb_posts.post_id 
WHERE phpbb_topics.topic_id > 5
AND phpbb_topics.topic_id < 15

Now at the results of that query at the bottom of the page is export click that and select Custom - display all possible options select the format as CSV and check the Put columns names in the first row check box.

Upload that file somewhere and post the link here (or send me a DM on Twitter) and I can have a look at exactly what is going on.

Edit: fixed mysql code formatting