In my system, the only way to make everything work out of plugging it to the n900 is by plugging it first to my Cyber-Power Hub. If I don't do that first, always sounds like there's something in the connection because it never detects or keep saying "device no accepting address x, error y". SOMETIMES it will detect, but is REALLY difficult.

SO, I would recommend to, before trying to use H-E-N, to use some GOOD/BRAND hub to filter out any noise.