Found a fix!
* Close Windows Sidebar. To do so, right-click on the Sidebar icon in the Notification area and click Exit
* Open an elevated Command Prompt window.
To do so, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
* In the Command Prompt window, type the following and press ENTER:
Similarly, run these commands:
If the registration was successful, you'll see the message DllRegisterServer in <filename> succeeded for each command executed. Open Windows Sidebar (sidebar.exe) and check if the problem is resolved. Move the gadgets to the place you want them and reboot. Problem will be fixed.