Squash - leaves turning white and dying

[The Black Thumb]

Is this normal when the squash plant is at the end of the season and on its way out? It doesn't seem like its powdery mildew, based on the explainations on the site. I am going to treat with a fungicide but just wanted some feed back before I went to work on the plants tomorrow. They are still producing fruit, but the leaves are in trouble. I have another plant in another part of the garden and it is healthy as a horse, which leads me to belive these are sick and not just at the end of their rope.

[stella1751]

The Black Thumb, I've grown a few cucumbers, and my money's on powdery mildew That's the most common cuke problem, in my experience.