I'm doing some modifications to a theme for a client. (I didn't develop the theme.) I registered two sidebars and added widgets to them. In the process, all of the widgets I had added to the right sidebar disappeared, both from the site and from the dashboard. I re-input them, finished the left column, checked everything, and closed the tabs. I e-mailed the client, and they came back with a reply that everything had "disappeared". Sure, enough, it had. I tried this fix by Justin Tadlock, in functions.php: http://justintadlock.com/archives/2009/03/03/widgets-reset-wordpress-plugin
I re-input the widgets, checked the browser, and everything showed up fine. However, I signed out, signed back in, and they were no longer in the dashboard. I checked the site and fortunately they are still appearing there. But, again, in the admin panel, the sidebars are empty (none of my widgets are showing up).
The frustrating part is these are mostly text widgets. And, there are several of them. So, it takes quite a bit of effort to copy/paste them each time.
Additional info: I did try deactivating and then reactivating the theme, but that didn't help.
Any idea what could cause this? Any help is greatly appreciated.