ess and debug package

[Angel -]

I was trying to use the new debug package from within emacs, I get the 
following error:
>library(debug)
Loading required package: mvbutils
MVBUTILS: no "tasks" vector found in ROOT
MVBUTILS loaded OK
Loading required package: tcltk
>mtrace(glm) # turns tracing on
>names( tracees) # "glm"
[1] "glm"
>names( tracees) # "glm"
[1] "glm"
>glm(stupid.args) # voila le debugger
Error in savehistory(file) : no history available to save

Has anybody been more succesfull?
Thanks,
Angel