I mixed my first batch of Dektol from the new, plastic packaging and panicked when it turned dark brown. So dark I couldn't see if the crystals on the bottom of the pot were dissolving. I've read posts about Kodak changing some suppliers and I guess this is another example of inadvertent product change. I went ahead and used it, returning to a negative that I had been working on. The result seems to be identical, so my concern was for nothing.
If you're mixing Dektol, notice if the crystals in the bag are a pale sand color - that's the stuff that will mix to a dark brown with a disgusting scum on top. But it works.

[IMG]PalouseFalls I LFF by John Olsen, on Flickr[/IMG]