Gus - When you changed you haldex fluid did you do a number of fluid changes or just a drain and replace?
If it was just the latter, I'd bet a pound to a penny your fluid is still manky.
The colour of your drained fluid resembles the colour of mine when I drained it. I did not need my car for a couple of days so I left the fluid standing overnight and then re-used the upper syphoned liquid and new fluid to "wash out" the haldex unit. I did this a total of about 6 times ( I used about 2 litres of new fluid + the best of the rest fluid) and it took this number of washes/flushes to get a reasonable coloured fluid out of the haldex. Each time I blew through the plastic tube I was using to drain the Haldex to disturb as much sediment as possible.
Additionally when the Haldex was filled did you remove 100ml? It might not be necessary on the modern units, but it was certainly a recommendation of owners for the P2 cars.
Cheers
Bob