Maybe a humidity issue? I've found that with some of my cattleyas that had past root damage, the leaves come back a little if I wipe my wet fingers over them and let the water soak in... I do it maybe every other to every third day and it seems to help a little.
The new growth always seems to grow the roots while the old stuff just sits and slowly withers away... It's sad... But I guess its the price I pay for damaging those roots.