Dear charmalu,

Thanks so very much for your pointers! The links you provided are really very helpful. I'm inclined to think you're spot on ... one or more components (probably plastic) went south on me. Given everything I've tried, and it being very loose on the driver's side, I think pulling the shifter apart is the next step. (Sigh.) I'll bet you're right. I'll post back here when I've made any progress. Thanks again!