Yes! The manual is useless. Trying to figure out also... http://www.rpod-owners.com/forum_posts.asp?TID=9487&title=thule-awning-arms-on-179
Are you talking about when you tuck the legs back into the main awning to close? When you put the leg ends in, go the other (outer) ends and push the snap lock into place. This seems to keep everything in place. Or are you talking about locking the extensions? Pull/push the lock tab all the way in one direction or the other...like 180 degrees from where it is unlocked. Don't know if that makes sense??
Don't bother looking on the Thule website...I scoured it for more info. Their videos are also about as useless as the picture book. Don't understand why they use NO words to help explain.