since my ISP is not offering IPv6 for the moment, i decided to use a tunnel from HE, however i have a problem with my DNS's (infact even with public ones like OpenDNS/GoogleDNS) and the problem is that they don't have that good support for IPv6. HE offers a DNS solely for IPv6, but my connection uses it even for normal IPv4 AAA names, so is there a way to set my tunnel to use only HE's DNS for IPv6 connections ONLY. What i mean is the HE's DNS to be used only for AAAA queries. Im using Windows7.
in general IPV6 lookups take precidence over ipv4 lookups. If a domain name has both, and you have IPV6 set up, you SHOULD connect to the ipv6 site preferentially to the ipv4 and fall back to ipv4. In my experience, 184.108.40.206 seems to do this at the very least, so you shouldn't need to use a ipv6 only dns.
Set the ipv6 dns as the primary, and your normal one as the secondary and it ought to work as you need it to.
I doubt you can set your computer to do AAAA lookups via the HE DNS servers, and all other queries use your IPv4 DNS servers. Do you mean that public DNS servers don't have ipv6 addresses? That they don't support AAAA lookups well? Does HE say that they will only reply to AAAA queries, and not A queries?