I had successfully blocked all minechem liquid dimlets in my pack. Now, today, I added a few custom material dimlets, and in addition to those new dimlets, all of the minechem dimlets are back. Have triple-checked that I didn't do anything to my original modban line.
This is RFTools 4.23 for MC 1.7

Never mind, being a dummy ... had an error in my config that cause it to be replaced with a fresh file during startup, but since I never closed the file after editing, I didn't notice.