[Seaside] Isolate doesn't seem to work

[Andres Fortier]

Hi list,
         Sorry if this is a newbie question. I need to avoid a user 
re-submitting a form by using the back button and I thought #isolate: 
was the way to go. However, I don't seem to be able to put it to work. I 
tested two simple examples (the one that comes with the seaside 
installation and the one in David Shaffer's tutorial) and both of them 
fail in the sense that it allows me to navigate with the back and 
forward button as much as I want. One of the examples is:

WATask subclass: #IsolateExample
...
go
	self inform: 'Before isolate'.
	self isolate:
		[self inform: 'Step 1'.
		self inform: 'Step 2'.
		self inform: 'Step 3'].
	self inform: 'After isolate'.

Once I end in the 'After isolate' page, I can use the back button and 
navigate 'Step 3' -> 'Step 2' -> 'Step 1' -> 'Before isolate'. As a 
matter of fact I can move with the back and forward buttons as if the 
"self isolate:" part wasn't there. Is this the expected behaviour? 
Should I set-up seaside in a particular way to support isolation? Or 
have I misunderstood the purpose of #isolate:?

Thanks in advance,
		  Andrés