Opening the Smb4k GUI does not help. Nowhere can I find this particular share in the list. It appears that there is no way to clear this share and prevent Smb4k from mounting it the next time it starts. After spending a week looking at this warning pop-up message, I decided it was time to hunt this setting down. This walk-through is on KDE4.
Open Dolphin (KDE's file manager) and navigate to /home/.kde/share/apps/smb4k. This folder is under your user-id. Remember files and directories that start with "." are hidden and you have to tell the file manager that you want to view them. For Dolphin you can switch viewing hidden folders on by selecting View and then Show Hidden Files.
In the smb4k folder you will find the configuration file "custom_options.xml" that contains the mounted shares.
Very important: you must shutdown Smb4k before editing the configuration file (Smb4k will overwrite your changes if you don't).
Click on the file and it will open up with Konqueror. The offending share is NAS1/photo. The file that we are looking at here is actually a XML file. Lets use Konqueror's built-in editor to make changes to this file.
Select View from the menu options, View Mode and then select the Embedded Advanced Text Editor option.
A share definition is contained within the options tag. I want to delete the NAS1 share. Click and drag with the mouse so that the first options tag is highlighted. Select Edit and then Cut from the menus to delete the selected text. Click on save icon to save the file to disk. Konqueror will also make a backup of the file for you.
You can now start Smb4k and no more complaints about that missing share.
