Dojo Toolkit: Issue on Floating Pane when closing and reopening it

[spidercode]

In closable floatingPane, when I close the FloatingPane and try to reopen it, it throws error.

There seems to be issue in Dojo Framework itself cause I can face the same issue in Documentation sample itself.

For sample, you can refer to the page: dojox.layout.FloatingPane

in this sample follow below steps to reproduce the issue:

1. Click on Run button of Programmatic example
2. Click on Show me (It will show the floating pane)
3. On the top right corner, click on close button to close
4. Click on Show me button again. (This will not work)