I DO have ipv6 enabled and all my devices (iPad1, iPad2, Touch, 2 iPhone 4s's and other WiFi computers) ALL access my network perfectly.
With a new iPod Mini, the WiFi was SO sporadic that from one minute to the next there would be no connection. I tried everything, reset the Mini, reset the network settings, etc. reset the router, reconfigured everything, but nothing helped. I finally exchanged the Mini where I bought it for a new one. And now I've got the SAME problems!!!
Cannot even do an iCloud backup as it starts just fine, reports the backup will take about 7 minutes, but then stalls with about 6 minutes remaining. Then after awhile there's a message that the last backup could not be completed.
The Mini would be great, but not with flakey WiFi. This one's going back to the dealer as well. SIGH
Not ready for prime time.