As LoadWB says, it needs some changes in local security policies.
I managed to see my Win7 laptop and my Win7 Home-Server from my Amiga using SMBFS (the manual way) but despite being able to see every file and folder, everything I copied to Amigas hard drive was corrupted and bigger in size! Didn't have much time to troubleshoot it but I will certainly try again soon and report back with my findings.