I just tried with two other PCs and same problems happen to them too. I also tried with openSUSE 11.3 and it too doesn't work, so this could still be a router issue. Maybe I'm having firewall problems? But if that was the case, everything would be working fine with firewall off.
whatismyipv6 only works over IPv4.
Here are some pings and tracerts:
Pinging whatismyipv6.com [2001:4870:a24f:2::90] with 32 bytes of data:
Reply from 2001:4870:a24f:2::90: time=222ms
Reply from 2001:4870:a24f:2::90: time=217ms
Reply from 2001:4870:a24f:2::90: time=221ms
Reply from 2001:4870:a24f:2::90: time=219ms
Ping statistics for 2001:4870:a24f:2::90:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 217ms, Maximum = 222ms, Average = 219ms
Tracing route to whatismyipv6.com [2001:4870:a24f:2::90]
over a maximum of 30 hops:
1 7 ms 1 ms 1 ms 2001:470:1f0b:de5::1
2 69 ms 70 ms 63 ms AndrejaKo-1.tunnel.tserv6.fra1.ipv6.he.net [2001:470:1f0a:de5::1]
3 57 ms 65 ms 58 ms gige-g2-4.core1.fra1.he.net [2001:470:0:69::1]
4 73 ms 74 ms 75 ms 10gigabitethernet1-4.core1.ams1.he.net [2001:470:0:47::1]
5 71 ms 74 ms 76 ms 10gigabitethernet1-4.core1.lon1.he.net [2001:470:0:3f::1]
6 141 ms 149 ms 148 ms 10gigabitethernet2-3.core1.nyc4.he.net [2001:470:0:3e::1]
7 141 ms 147 ms 143 ms 10gigabitethernet1-2.core1.nyc1.he.net [2001:470:0:37::2]
8 144 ms 145 ms 142 ms 2001:504:1::a500:4323:1
9 226 ms 225 ms 218 ms 2001:4870:a240::2
10 220 ms 224 ms 219 ms 2001:4870:a240::2
11 219 ms 218 ms 220 ms 2001:4870:a24f::2
12 221 ms 222 ms 220 ms www.whatismyipv6.com [2001:4870:a24f:2::90]
Trace complete.
Tracing route to ipv6.l.google.com [2a00:1450:8004::68]
over a maximum of 30 hops:
1 1 ms 1 ms 1 ms 2001:470:1f0b:de5::1
2 67 ms 63 ms 64 ms AndrejaKo-1.tunnel.tserv6.fra1.ipv6.he.net [2001:470:1f0a:de5::1]
3 58 ms 57 ms 60 ms gige-g2-4.core1.fra1.he.net [2001:470:0:69::1]
4 61 ms 88 ms 60 ms de-cix20.net.google.com [2001:7f8::3b41:0:2]
5 61 ms 64 ms 60 ms 2001:4860::1:0:11
6 74 ms 71 ms 70 ms 2001:4860::1:0:fdd
7 78 ms 74 ms 74 ms 2001:4860::1:0:60d
8 73 ms 245 ms 78 ms 2001:4860::2:0:612
9 75 ms * 76 ms 2001:4860:0:1::9d
10 76 ms 74 ms 73 ms 2a00:1450:8004::68
Trace complete.
Tracing route to orange.kame.net [2001:200:dff:fff1:216:3eff:feb1:44d7]
over a maximum of 30 hops:
1 4 ms 1 ms 1 ms 2001:470:1f0b:de5::1
2 65 ms 68 ms 64 ms AndrejaKo-1.tunnel.tserv6.fra1.ipv6.he.net [2001:470:1f0a:de5::1]
3 60 ms 65 ms 56 ms gige-g2-4.core1.fra1.he.net [2001:470:0:69::1]
4 60 ms 58 ms 58 ms xe-0.de-cix.frnkge03.de.bb.gin.ntt.net [2001:7f8::b62:0:1]
5 62 ms 62 ms 64 ms ae-0.r21.frnkge04.de.bb.gin.ntt.net [2001:728:0:2000::2]
6 64 ms 69 ms 67 ms as-1.r23.amstnl02.nl.bb.gin.ntt.net [2001:728:0:2000::13d]
7 71 ms 65 ms 63 ms as-0.r22.amstnl02.nl.bb.gin.ntt.net [2001:728:0:2000::11]
8 375 ms 384 ms 373 ms as-0.r25.tokyjp01.jp.bb.gin.ntt.net [2001:418:0:2000::16]
9 449 ms 372 ms 418 ms ae-9.r20.tokyjp01.jp.bb.gin.ntt.net [2001:218:0:2000::1c5]
10 377 ms 379 ms 378 ms po-1.a15.tokyjp01.jp.ra.gin.ntt.net [2001:218:0:6000::10e]
11 333 ms 329 ms 334 ms ge-8-2.a15.tokyjp01.jp.ra.gin.ntt.net [2001:218:2000:5000::82]
12 331 ms 341 ms 332 ms ve44.foundry6.otemachi.wide.ad.jp [2001:200:0:10::141]
13 333 ms 333 ms 331 ms ve42.foundry4.nezu.wide.ad.jp [2001:200:0:11::66]
14 331 ms 329 ms 331 ms cloud-net1.wide.ad.jp [2001:200:0:1c0a:218:8bff:fe43:d1d0]
15 331 ms 334 ms 330 ms 2001:200:dff:fff1:216:3eff:feb1:44d7
Trace complete.
Tracing route to orange.kame.net [2001:200:dff:fff1:216:3eff:feb1:44d7]
over a maximum of 30 hops:
1 4 ms 1 ms 1 ms 2001:470:1f0b:de5::1
2 65 ms 68 ms 64 ms AndrejaKo-1.tunnel.tserv6.fra1.ipv6.he.net [2001:470:1f0a:de5::1]
3 60 ms 65 ms 56 ms gige-g2-4.core1.fra1.he.net [2001:470:0:69::1]
4 60 ms 58 ms 58 ms xe-0.de-cix.frnkge03.de.bb.gin.ntt.net [2001:7f8::b62:0:1]
5 62 ms 62 ms 64 ms ae-0.r21.frnkge04.de.bb.gin.ntt.net [2001:728:0:2000::2]
6 64 ms 69 ms 67 ms as-1.r23.amstnl02.nl.bb.gin.ntt.net [2001:728:0:2000::13d]
7 71 ms 65 ms 63 ms as-0.r22.amstnl02.nl.bb.gin.ntt.net [2001:728:0:2000::11]
8 375 ms 384 ms 373 ms as-0.r25.tokyjp01.jp.bb.gin.ntt.net [2001:418:0:2000::16]
9 449 ms 372 ms 418 ms ae-9.r20.tokyjp01.jp.bb.gin.ntt.net [2001:218:0:2000::1c5]
10 377 ms 379 ms 378 ms po-1.a15.tokyjp01.jp.ra.gin.ntt.net [2001:218:0:6000::10e]
11 333 ms 329 ms 334 ms ge-8-2.a15.tokyjp01.jp.ra.gin.ntt.net [2001:218:2000:5000::82]
12 331 ms 341 ms 332 ms ve44.foundry6.otemachi.wide.ad.jp [2001:200:0:10::141]
13 333 ms 333 ms 331 ms ve42.foundry4.nezu.wide.ad.jp [2001:200:0:11::66]
14 331 ms 329 ms 331 ms cloud-net1.wide.ad.jp [2001:200:0:1c0a:218:8bff:fe43:d1d0]
15 331 ms 334 ms 330 ms 2001:200:dff:fff1:216:3eff:feb1:44d7
Trace complete.