I do not have the Large Assembly option turned on, so this shouldn't be the problem.

This is a post from another forum:
"Unfortunately, weldments do not update automatically even when rebuilt to reflect the changes in the profile sketch. In order to update the structural members it is necessary to edit the feature, change the profile and then change back to the desire profile to update the member."

Does anyone else disagree with this or know a way around it? We are going to start a big project using weldments, but if I can't find a solution to this I'm thinking about not using weldments.