I saw that you were recently active in the support forum here, so I thought this would be the best way to get in touch with you.
Over at WP Last Login's support forum I received a bug report which was traced back to WP Members.
wpmem_add_user_column_content() does not return the passed value per default, but a user meta for the column's name. Unfortunately this breaks other plugins that also hook into
It would be great if you could change to where
$value only gets changed in instances where it is you plugin's column.
Please let me know if you have any questions!