This sounds similar or the same as the bug report I posted a couple of weeks ago... see http://groups.yahoo.com/group/squeak/message/33698 .

I don't think the problem necessarily depends on the "debug it" feature... inserting a "self halt" and using "do it" revealed the same problem. (at least for me, I haven't tried stepping through your example)  My hunch is that the problem is related to the various BetterDebugger enhancements in updates 4322-4324.

- Doug Way
  dway at riskmetrics.com


Ross Boylan wrote:
> 
> Summary: In a debug it, the list of variable names shown on the lower
> left pane is always that applying in the original context of the debug
> It.  It may matter that the debug it started from within a regular
> debugger window.
> 
> For the second time, I am seeing the wrong variable names listed on
> the lower left pane of the debugger.  In this case, it is the names of
> the instance variables for the object one frame up the stack that are
> showing.  If I try to click on one, I get "subscript out of bounds"
> (if it is far down the list) or I see the contents of the proper
> instance variable in the next pane over to the right.
> 
> In other words, the problem seems to be strictly with the display of
> names.
> 
> The earlier problem, noted in passing in by [BUG] report of a couple
> days ago, was one in which instead of names I saw numbers.  As in that
> case, if I click on "all instance variables" the info is good.
> 
> How I got to this point:
> 1. insert a halt in some code.
> 2. the running process hits the code and raises a debugger
> 3. I perform a "debug it" on the code in the debugger
> 4. In the second debugger, I follow through a few sends
> 
> AHA: the problem is that the list of variables in all stack frames is
> the one that originally applied when I did the debug it.
> 
> I don't recall if the earlier error involved a debug It.
> 
> Last update: 4418