Lord Ashcroft

I know this is bit of a non-story (and frankly, the BBC are being typically biased over it), but let's consider some facts:-

1. Ashcroft told Hague something
2. Ashcroft agreed to be a non-dom with the Cabinet Office.
3. Labour are complaining about his status.

Are Labour saying that they didn't know what the deal was with the Cabinet Office? Why are they making hay over something that was agreed by the civil service while they were in charge?