Here's my traceroute:
traceroute to www.byond.com (216.240.131.151), 30 hops max, 40 byte packets 1 adsl-gte-la-216-86-198-gateway.mminternet.com (216.86.198.1) 31.506 ms 31.686 ms 32.085 ms 2 adsl-gte-la-216-86-207-gateway.mminternet.com (216.86.207.1) 28.307 ms 57.054 ms 27.402 ms 3 airborne.webvision.com (216.240.138.1) 24.174 ms 62.833 ms 24.230 ms 4 10.255.255.128 (10.255.255.128) 74.982 ms 26.628 ms 57.660 ms 5 10.255.255.128 (10.255.255.128) 48.029 ms !X * 23.640 ms !X
Here's something odd: the 10.0.0.0 subnet is reserved for private class A networks, not to be used anywhere on the internet itself. So some machine out there (presumably on webvision's network) is sending back bogus "communication administratively prohibited" messages (that's what the !X means). Maybe if you get the DreamHost guys working on it and I'll try to get my ISP guys on it, we'll find a solution.
Just for reference, a traceroute from any other host generally ends with these lines:
8 wvision-la-oc3-gsr1.webvision.com (63.149.192.126) 51.350 ms * 38.747 ms 9 * * * 10 * * * 11 basic-argon.polaris.dreamhost.com (216.240.131.151) 56.331 ms 52.239 ms 54.637 ms
Looks like you have it all under control. I double checked the traceroutes and your correct on everything you posted. Basically, it looks like a bottleneck inside the DSL net itself but a traceroute isn't sufficient to isoloate the problem.
Good luck!