Thanks for the reply - I was afraid this would be the case. I can deal with the DNS port directly on Windows, but can't make it work on my iPad, which is why I was hoping the router could be set up appropriately. I'm on satellite internet (WildBlue) and they justify the DNS hijack by claiming it allows them to provide better service. In theory this might be true, but they don't seem to be able to run a DNS server to save their lives.
I'm pretty sure the N300 can be flashed to dd-wrt, but I was hoping to avoid that.