I recently retired my 20+yr old VC dutchwest cat and bought a new non-cat insert. The old cat wasnt cruisin' like she used to (even with a new combuster) and I noticed that the top cover wasnt fitting right anymore. It seems the cement got old and gave out a bit on the right , rear sidewall, causing the sidewall to 'slip' up a bit during a small maintenance move. Im guessin that she has some small air leaks, b/c even with a new combuster, she was burnin up a full load of oak in just a few hours. Does anyone know what ELSE could be causing this lackluster performance? The liner is relatively new, and in great shape. There are no VISABLE cracks/leaks, and all the gaskets are tight too. Im out of ideas. Any input would be apprieciated.