So I'm a bit baffled by this recent occurrence. Did a big shoot a couple of weekends ago, around 10 sheets of 8X10 and 20 sheets of 4X5. I started developing them in my usual manner with PMK Pyro in a Jobo. I have both drums, one for 5 sheets of 8X10 and the one for 10 sheets of 4X5. I've been getting pretty consistent results with them for the past couple of years, but this time, probably because of the importance of the project, most of them are crap. There is evidence of uneven development on some negatives, like no developer got the bottom of the tubes, streaks in some and a couple of 4X5's were blank. I know I could have a couple of things going on, definitely a Zebra in the works, but when I shot some 8X10's today and processed them with BTZS tubes, perfect! I have more 4X5's to develop and will use BTZS tubes for them to confirm my theory. So, how finicky really are these damn Jobo's? Should they be perfectly level? I use a drum roller, a bit worn out, and switch directions at even intervals. I use 500ml of chemistry, which should be more than enough. The only difference I can tell from last time is that I placed the roller on a different base in the sink. Should it have some grade to it? It appears that the chemicals don't get sloshed all the way in and out of the tubes. Nothing that drastic has changed in my method, or at least that's what I think. Thanks in advance for any advice I can get. If I can't resolve this, I'll go back to BTZS and you might find a couple of Jobo's on the For Sale list.