Just to be clear, with a filtered faceplate the extensions can't be used for ADSL. There's nothing wrong with your wiring - that's how it's supposed to work. If you have to move the router away from the master socket, you have two options:
1. Replace the filtered faceplate with an unfiltered one. Your extensions will then be live for ADSL, but with the disadvantages mentioned by AdrianH.
2. Wire up a separate extension for the router to use, connecting it to the A and B terminals in the filtered faceplate, not to terminals 2 and 5 as used by the normal extensions. Most filtered faceplates these days include A and B terminals, but if yours doesn't then you will need to replace it with one which does, or use option 1.