To replicate, drag an XtraMap control onto a form, click its Smart Tag, click on the "Connect to OpenStreetMap Server" link button and then run the application. The MapControl will not display anything.
Click on the MapControl Smart Tag again and then on the "Edit Layers" link button. If you expand the properties of the Images Tile Layer that was automatically created, you'll see the DataProvider.TileUriTemplate is "http://{0}.tile.INSERT_SERVER_NAME.com/{1}/{2}/{3}.png".
If you add another Images Tile Layer via the Layers Editor and set the DataProvider to OpenStreetMapDataProvider, the TileUriTemplate is the correct "http://{0}.tile.openstreetmap.org/{1}/{2}/{3}.png" template.
The "Connect to OpenStreetMap Server" link button in the Smart Tag popup should replicate the process of adding an Images Tile Layer and use the correct TileUriTemplate.