sucks,
i would seriously consider getting it re-done (the acl). normally, i'd tell someone in their 30's that they don't have to have a working acl. if i tore mine tomorrow, i'd consider non-op treatment, as i no longer do 'cutting' activities (soccer, football, tennis, etc). most people can stabilize their knee through extensive strengthening of the quad muscle so that they can run and do most normal activities without an acl. if you're getting instability in the knee with normal walking, to the point where the knee buckles and you're tearing the meniscus, then it might be time to consider another acl reconstruction.