I am currently crocheting this adorable little creature:
www.amigurumipatterns.net/Cartoons-and-Games/Stitch/
I'm currently working the body which is 18dc dark blue then 18dc light blue then 18 dc dark blue
There is also a decrease of 9 stitches every 4th row, but the decrease is distributed evenly over the dark and light blue.
So I should end up with a block of light blue in the tummy area.
I've worked 8 rows with the colour block in and my boundary has gradually shifted about 5mm anti-clockwise. (My colour change boundary looks like / iyswim). It is the same at both boundaries.
I've counted carefully and still have 15dark -15 light -15 dark so it doesn't appear to be a counting mistake. It apoears that my whole row has subtly rotated around.
As I say I am counting and doubke checking.