It's probably not a factor in your problem...
...but I have not personally used a single INNER JOIN in the last four or five years. If you are looking up details in one list based on the other list, use a LEFT or RIGHT JOIN, if only to make explicit your own logic.
Many fears are born of stupidity and ignorance -
Which you should be feeding with rumour and generalisation.
BOfH, 2002 "Episode" 10