Need quick query to update post count in flatforum table

I'm using the flatforum module, and also the phpbb2drupal module to convert my existing site to Drupal. This is working well, except flatforum's ability to track post counts for comments does not take effect on imported posts. I need to update the post counts in that table based on the posts in the comments table.

My SQL is beyond rusty and I've got my site down and being transferred right now so I was hoping someone could help me out with an SQL query to do this before I turn it live :)

In plain english, I need to update the flatforum table and set the posts field equal to itself plus the count from the comments table for each uid.

Thanks in advance!