eagle 737
Just out of interest, did you try tapping the guage?
Although I have never had an assymetric flap problem on the 737 it was an infrequent problem on the 747 classic where it was recommended that a 'technical tap' be applied to the flap guage in case a needle had stuck. (From dim recollection I believe that the assymetric protection came directly from the flap guage)
Regards
Exeng