Mine is solid, up or down, haven't used it enough to wear it out I guess.
Bernie has never said anything about his, and he's used it a lot, so I'd give Smith a call about it. Be patient with em tho, takes a while to get in touch with em every time I've tried, email worked best.
They did replace a defective peep slider for me, no charge, just took a few months.
Tim
http://www.smithenterprise.com/contact.html