Thank you for reply.
Please, try to reinstall Store Manager. Use its native uninstaller at Start/all programs/emagicone/Store Manager for Zen Cart/uninstall. Please, save all your configurations before uninstalling, so you could easily upload them to newly installed program.
You can save your store configuration file at: Store Manager > Preferences(F12) > Database Connection tab > Store Configuration section > Actions... > Save current configuration: http://screencast.com/t/Hmy0nUDBsHJc
Let us know how it goes!