Your cursor must be on a code line, not on a special "comments" line. I've had

the same behavior once. Just move down your cursor one or two lines away...

Are you saying you have succesfully detangled noweb embedded code? If so, ill have to take a look at the code to see where the bug is. It doesn't work no matter where i place my cursor. My tangled output is also different -

;; [[file:~/Desktop/test.org][/home/seth/Desktop/test\.org:2]]

(let ((x 1))

(message "x=%s" x)

;; [[file:~/Desktop/test.org][wrappable]]

(setq x (+ 4 x))

;; wrappable ends here

(message "x=%s" x))

;; /home/seth/Desktop/test\.org:2 ends here

Notice that detangling works if there is no noweb being used.