If you are using a custom Magento theme and are having problems getting extensions to display correctly on the frontend, there is a good chance that it is an issue of file location. Extensions usually install to default/default/ or base/default/ because there is no way for the developer of an extension to predict whether you are using a custom theme or what its name might be.

When using a custom theme, Magento will look in YOUR_CUSTOM_THEME/default/ directory for an extension’s .phtml, .xml, and .css files. If they were installed to the default or base directory, Magento won’t be able to locate them within the theme directory and consequently the extension’s output won’t be displayed.

To display the output of an extension, simply make sure that its files are in the correct locations. Check the base and default directories and see if there are any CSS, XML, or PHTML files for the extension. If so, move the files to the corresponding location within your custom theme.

Finally, refresh your cache and test that the extension’s output is correctly displaying.