Blank page on edit after collaborative editing switched off and on again

Steps

1. Find a page to edit
2. Switch collab editing off
3. Switch collab editing on
4. Edit the page you chose in the first step

What happened...

9 times out of 10 I am getting a blank page instead of the page contents when I click edit.

What should have happened...

Editor should have loaded with the content.

Workaround
Refreshing the page loads the editor fine and this only seems to happen to the page the first time after collab editing has been switched back on.