Thanks, that doesn't actually solve the problem. This is the way I see it:
You log in as admin.
You start webmaster mode.
You launch another customer window using the link provided.
From that window you login as a customer account to make webmaster mode changes to e.g. the checkout pages -this kicks you out of admin.
Another browser doesn't really solve the problem as the webmaster mode customer window is launched from whatever browser you're logged into admin with....
Lol, I think that makes sense!
Dan