I also have this trouble with my k-r. Why didn't they put kelvin select WB, manual WB selection in the menu is absolutely worthless. Even when I put it to some other setting (not AWB). Lets say Daylight, and fine tune it a bit into blue part. And if i take many pictures on that setting, camera is for some reason still changing the temperature of the shot. For instance, some images will be 5400 and then out of nowhere, there will be some that are on 5500 or 5300 for no apparent reason despite not using AWB. I have a college project for finals where I have to make stop motion and time-lapse video. And in early stages of development i noticed that JPEG shooting will not be an option for me because of this bug, to work around this problem i just shoot in RAW and fiddle with WB in post process. Lightroom is excellent for this job since you can batch edit thousands of "same" pictures with single click.
In extreme cases K-r that is on AWB will be unable to make up its mind over which temperature to use. I noticed this when i was shooting this time-lapse for the first time as a trial.just skip to 2:47, street light is hard tungsten, very very yellow, but snow reflects blue from the sky. If i had put camera to some other WB setting, even manual, it would do the same thing but not so dramatically.
Similar Threads 
