When I tried to get cb-sea-miniosx01.sj.mozilla.org to access cb-seamonkey-linux-01.mozilla.org:9010 I saw that it couldn't connect, so we need a hole in some firewall for this. We'll need the same for the future cb-sea-miniosx0[2345] machines coming in bug 526208 but I guess I'll need to request their access once they are here and set up, right?

Ah, this is a host configuration problem. The size of cb network was expanded earlier this year. The old netmask, 255.255.255.224, is now too restrictive and hosts having IP with a last octet higher than .32 will not be accessible. The proper netmask is 255.255.255.192. Change the netmask on the interface of your host and you should be fine.

Thanks for the pointer, looks good with the changed netmask.