How to logon with local account? RODC “There are no logon servers to process your request”

RoDC DNS replication isn't a whole lot different than DNS replication for other domain controller computers (see the entry in the table titled "Read-only domain controller support" here for details), though you do need to have at least one Windows Server 2008-based DNS server hosting a writable copy of the zone (see the "Note" in the section titled "DNS updates for clients that are located in an RODC site" in this document for details). It sounds like you've got a writable Windows Server 2008 DNS server (the one in the data center), though, so that shouldn't be your issue. That W2K8 DNS server computer in the data center does have an "NS" record published in the DNS, doesn't it?

Are you sure you're getting replication to the RoDC machine? I'm getting the feeling that it's not receiving replication at all. A quick check w/ REPLMON (from the Windwos Support Tools) or your favorite replication monitor would let you know the last time the directory partitions it hosts were updated.

I'd hazzard a guess that it's related to cached credentials... when you created the new user and logged in as it, you "wiped" the cached creds for your domain account. I suspect that the "fix" would be to connect to your work LAN again - then a DC would be available to authenticate you, and the cached creds would be restored - but it'd probably break again the next time your brother logged in....

It does kinda beg the question - are your IT peeps happy with you creating local logins for family members on your work kit? I know I wouldn't look kindly on my users trying this!! ;-)

Just my $0.02...