I have a Windows 7 (64 bit) development machine, on which I set up a new Ubuntu 12.04 Server (32-bit) installation in a VirtualBox VM & included LAMP, SSH & Samba in the installation. When complete I configured Samba and shared the /var/www folder for read/write access. However I could not access the Ubuntu 12 server from my windows 7 PC, but I had full read/write access from a Windows XP system on the same network.
I searched the internet for a solution, but couldn't find anything conclusive, however I did find some posts where others had similar problems, and one reference which said that the version of Samba in 12.04 was different than in earlier Ubuntu releases.
I was getting nowhere with 12.04, so I set up another VM and installed Ubuntu Server 11.10, this time from a pre-built VB image and configured it the same way as the previous 12.04 server. Same user, same passwords, same shares, same everything as far as possibel, and it works swimmingly. I have full R/W access from both Windows 7 and Windows XP, and can map drives and copy files to & from the sahres without any problems.
I'm fairly new to Linux/Ubuntu, and I don't know how to troubleshoot this type of problem, so I'd be grateful for anyones comments & help.