I've been developing film in print drums for a while and never noticed any uneven development. I've used D76, HC110 and Rodinol (1:50). Now I have some shots that I believe I grossly overexposed so I decided to try divided pyrocat to limit the development of the highlights. It seems to be working except I'm getting more development on one of the edges. Any idea on why I'm only noticing this problem with divided pyrocat MC (A1:20,B1:20)?

Thanks
Chris