[ESS] How to recover the prompt after an error sourcing a .R file

[Pedro de Barros]

Dear All,

I am using XEmacs+ESS (5.3.7) under windows, using John Fox's 
configuration files.
I am running R version 2.7.0.

The issue is as follows:
Sometimes, when e.g. sourcing a file that has an error, ESS reports 
(correctly) an error.
The problem is that after that, it seems to "loose" the prompt, and I 
cannot find out how to recover it.
I manage to "send" R instructions to the inferior R process (using 
C-l or C-c C-n) from a script buffer, but I cannot do things like 
e.g. q() on the R-buffer...

I am sure there is a simple way to solve this issue, but I have been 
searching for it for a couple days now, to no avail.
I would appreciate any suggestion you might have.

Greetings,
Pedro