I've been developing colur paper negatives with fairly good results, however I seem to be running into a problem with the latest images I've developed. There is a blue gradient that goes across the entire paper.
This is not related to the image (the blue extends into the area covered by the sheet film holder).
I am using the Tetenal RA-4 kit. The process I use is:
Heat chems to 35 degrees in Jobo bath
Dev for 45 secs
Stop for 30
blix for 45 secs

Pictures I took last night are fine. Pictures I took today all have the blue on them.
Last time I had this, I dumped the developer and the blix. But this developer is only a few days old, so I dont want to dump it.
I read somewhere, that the blue means the blix is dead, so ive tried a longer blix (2 min) but that did not work.
Any ideas?
Thanks in advance