DHCP with Samba on the Amiga is very troublesome. I eventually gave up on it and switched back to static IP addresses.
You have two separate problems, one with Miami failing to acquire an address through DHCP, and the other with Samba.
In Miami, set the IP type, netmask, and gateway of your interface to DHCP. Then press the 'TCP/IP Settings...' button and enable DHCP there. Send your hostname as well. Set 'Get Dynamic DNS Servers' to 'verify&add'. Hopefully that will solve your general connection problem.
I've found however, that Amiga Samba is dumb, and can't figure out DHCP IP addresses. You'll need to manually adjust the interfaces line in smb.conf to whatever your current IP address is (your router can usually tell you this). You also need to have your hostname and current IP address as well as the hostnames and IP addresses of any machines you want to connect to listed in the 'hosts' page of the Miami database.
Yeah. Having to manually update all this for DHCP changes is extremely annoying. Unless someone else knows a workaround, I say try going back to static addresses.
