last_upd field in item table

Hi all,

the last_upd field in item table does not always reflect the date when the item was last updated in Agile.

for example, from the database i can query items that have last_upd set to today, but when i go to Agile client and search those items i don't see any updates happened to them from looking at the history tab.

what does this last_upd field really means?

thanks,

Abdellah