The lack of a where clause is pretty significant.
Whether I missed something as obvious as that or I already tried the "where" clause I guess is not clear- but I only asked because I tried it many different ways with no good result.
Actually, it was:
<cfquery name="update" datasource="#Request.BaseDSN#">
SELECT queue_ID, q_user_ID, user_ID, office_ID
FROM main_helpdesk, lookup_user
<cfquery name="updatedata" datasource="#Request.BaseDSN#">
SET q_office_ID = #office_ID#
WHERE q_user_ID = #user_ID#