Ext Designer 1.1.2
Windows XP Pro

Steps to recreate:

1. Open a project and create a data store (only tested with JSON store)
2. Export the data store as a component
3. Open a new project
4. Import data store xdc

Data store appears in the Components section of the right hand pane and, when you export the project, both the datastore js and ui.js files are created.

The imported data store should appear in the Data Stores pane. There should be no *.ui.js when exporting the project.