Tim,
The best way to get back to your main document after switching to another file is to use the Open Recent option. Since you've opened some Backups, there's a slight chance that the document you're looking for isn't still available under the recent items, but to try the option, go into the application, go up to click the File menu at the top of the screen, slide down to hover over 'Open Recent', and then choose from any files listed there.
If you're unable to locate your up-to-date information, we can check your recent system logs to determine the location of all documents you've used lately and direct you to what you need. To gather the logs, open the application, go up to the Help menu while holding down the Option key on your keyboard, choose 'Go to System Logs folder', and then locate all items that have 'system.log' in the name. Those logs can all be sent to us at
support@splasm.com and we should be able to get back to you via email with steps for bringing your data back up.