What happens if you start Caja and enter smb://ip-adres/sharename in the location-bar (just click on the icon that looks like a piece of paper with a pencil in front).
You should get a pop-up which asks for a username and password. You should be able to leave them empty when the rights on the windows-share are correct.
Another thing you can try is to open up a Terminal and type the following command, needless to say that you should replace ipadres with the actual ip-address of your windows machine and sharename with the name of the windowsshare 
sudo mkdir -p /mnt/ntserver
sudo mount -t cifs //ipadres/sharename -o username=,password= /mnt/ntserver
The windows share should then be accessible with:
cd /mnt/ntserver
ls -la
This by no means is a solution, I am just curious what happens.