It's a systemic problem at D-Link. I have reported issues with the DVA-2800 and nothing was done. The problem is too big.
Their developers don't do unix mindset, they cobble together bits of code and script in a seemingly random fashion.
Just ssh into one of their boxes (probably any) and look around. I got some features running that didn't run because of typos in scripts, remounted the root partition rw and made some changes to the firmware,