I'm running a load now, the first one since the vinegar cleaning. I also noticed that my Cascade is, indeed, phosphate-free. My guess is that this is because I purchased it at Costco, which of course feeds the lowest common denominator, so they probably ship the phosphate-free version of their product to their stores so they don't have to carry both varieties (because if there's one thing Costco hates, it's variety).

I'll swing by the grocery store later today and pick up a small box of Cascade (if it's not phosphate-free) and try that in the next load.

I can't remember when I started getting Cascade from Costco instead of the store, but I thought it was before this problem started happening...

Does anyone have a link to something that tells why phosphates might be harmful?