I got something on one of my plants that looked like this last year as well, but there was similarly no leaf stunting. I took a chance and left the plant in, and it continued to produce normal-looking and -tasting fruit until it was taken down by bacterial wilt and powdery mildew.
And the year before that, I was growing sanditas/mouse melons, and one of my plants got some weird yellow speckling but continued to produce fine.
But I don't know of any nutritional or physiological problem that looks like this. Sure looks like CMV, but there's no leaf distortion.
I have another plant right next to this one that shows no discoloration at all.
Anyway, I'd appreciate a more experienced eye and opinion on this.
The variety is H-19 Little Leaf. Leaves are not stunted--they're normally smaller than most cukes.
Wetness is due to the fact that it started raining just as I was snapping these photos.
Click for full-size photos.
