Q: Database error attatching Miscrsoft office 2007 files.

A: This attachment issue is related to the long MIME type of MS office files.
   For these files, the mime type is something like
   "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
   and which exceeded the limit of 50 chars of the content type column in 
   the file table.

   This problem was fixed in v5.5.1. But for existing projects, you need 
   update the file tables manually.

   For each project, there is a table called projectId_file,
   and there is a column called content_type, it was varchar(50).
   You need change it to varchar(255).

   You can do this manual change the tables before upgrading.
   It should fix the problem right away, no need to restart app server.

   To avoid problems for new projects, if you don't upgrade, you need
   change the sql file, create_table_file.sql and create_table_file_mysql.sql,
   from  content_type VARCHAR(50) NOT NULL,
   to   content_type VARCHAR(255) NOT NULL,

   And restart the app.