Catt. leaf looks like an overripe banana

[fyschebone]

My Catt. 'paradise' (Blc. Hawaiian Passion x. Blc. Sakurahime) has started to look like an overripe banana (see attached). Here's a link to a time when it was healthy and in bloom:

http://www.orchidboard.com/community...d-me-home.html

Any thoughts on what could be causing this type of leaf problem? You can see new growth on the left side of the picture.

It sits in a relatively bright south facing window, but receives no direct light after 9am. The three other Catts and four phals in the same window are doing excellent. It's in the same medium that it was in when it was purchased four months ago. It was blooming when I purchased it. It is elevated above its saucer and so never sits in water. It is misted lightly every other day and soaked once per week.


Any thoughts?