I've noticed this for a while, now that I have a project with many walls it's a hassel.
Problem: When I created my walls with a fill pattern using a solid for its class they are all filled with that pattern. But, when I change to a different pattern only a few walls in that class change. The others remain in the old pattern. The only way to get the remaining walls to change is to select them, change their class and change it back again. Any thoughts?