[dspillett]

Make sure you update the site to state that it is currently blocked by these ISPs, you don't know why, you have asked them to investigate, but you have not heard nothing back and until they respond it is completely out of your control.

That way anyone who can access it from work but not home (for example) or recommends the site to a friend who finds it doesn't work, will have a clue as to what the problem is (and it isn't your fault).

If your site is of significant general interest then this may also increase the chance of the ISPs acting quickly.