samba and swat are two seperate services. swat is a web based tool for creating and changing samba's configuration file smb.conf. samba consists of two daemons smbd and nmbd.
Check the processes to verify that swat is actually running with the console command top or ps. Also check that smbd and nmbd are running. swat might not display a web page if samba isn't running.
Since you do not get a connection error swat might be running. I do not run swat because I find it just as easy to edit the smb.conf file using a text editor. I do not know how swat generates its web pages. You also might want to look at www.samba.org
for documentation help.