I just got some very disappointing results using rodinal on pan f plus. The film was barely developed at all - both frame numbers and image highlights are just barely visible. I bought two new bottles of agfa rodinal back in January of this year, and my first rolls with them came out fine (they were acros). Then I didn't use the stuff for a half year, and I just souped these rolls today which did not turn out. I used dev times from the massive dev chart: 11 minutes at 20 C with 1:50 solution. It seems my rodinal has gone bad even though I tightly capped the container and even purged with CO2. Does anyone have any idea why this might have happened? One of the main reasons I decided to go for rodinal was its purported long shelf life (and the fact that it is a liquid concentrate).