Ann: Half Year Financials 31 December 2013 , page-3

3Suns
I just started a thread same time as you, once you read it you might see some sunshine hopefully. The bulk of the impairment is a book value writing down the tax losses as I telegraphed would probably happen.
The losses are still available should NXS one day have a massive windfall, the accounting standards do not allow you to just carry them unless you can demonstrate with certainty that you can access or utilise the tax losses.
Fortunately by the skin of their teeth (no Crux write down) they avoid breaching the covenants on the Notes.