db_update query does not work properly
My first inclination is that this is a caching issue.

Other possibilities:


Is the node actually stored in the orders table?  Do you do the appropriate updates for the nodes table as well?
Is this in an incomplete transaction?  (db_transaction)
Have you checked the return value of the -&gt;execute() to see if it is returning the right number of rows?


Without a full description of what the variable $context and the table orders contains, it is hard to give any better answers.