That sounds a lot like a firewall blocking everything. However, I thought that the firewall (which has no GUI) was disabled by default.
Just a few things worth checking:
- Is the SAM on the same subnet, i.e., do all IP addresses have the same first three numbers (e.g., 192.168.0.x)?
- Have you actually installed the Samba services properly? It's not going to serve anything unless the smbd is running (nmbd should be running too). This doesn't explain why you can't ping the SAM machine from the other machines though.
- try accessing via IP address directly instead of name, e.g., \\192.168.0.2\share.
As to why the transfer in one way is faster than the other, I have no idea. Years ago I had set up Samba on my A1200, and it had a 0.5-1 second delay per file being copied. It made copying directories with many little files painfully slow. Windows networking is a complex beast, and you tend to get problems from time to time even with windows machines (e.g., one computer doesn't see the other computers, but can connect directly via IP address).
Hans