IPv6 tunnel and UTM 9

Hi All,

I have a question about IPv6/tunnel/UTM 9. I know this is not all about UTM 9 but can't find out what I'm doing wrong...
I have an account at sixxs.net and my tunnel is up and running, so far so good (it's a 6in4-static). Now I need to configure the "Prefix Advertisements" or "IPv6 DHCP" but I don't have no clue what the best solution is for me.

I tried both settings but my Windows 8 PC only receives a local-link IP (fe80:: )as gateway and not my UTM IPv6 IP. I can ping IPv4 address but not IPv6 addresses.
Must there be set extra PF rules now I have masquerading to allow LAN(4-6) to any...

Does someone have a good site/URL with a step-by-step guide to get this working properly? Or would someone be so kind to help me with it?
I tried to use the manual http://www.astaro.org/139118-post2.html but that didn't helped me :(

Hopefully someone is so kind to help me to sort this out...TIA