I have the same setup as you but with a DX7, if the tail is wandering in HH mode then your gain is too low, increase your gain about 5% at a time until the tail starts to wag when you hover, once you achieve this remove 3-5% gain and you're dane.

Even if you resolve this I would recommend you watch all of finless bob's vids because they are an excellent way to learn to setup your heli correctly since there are some things that words can not explain as good as images

Cheers
Rene