Rob, thanks for your explanation. I feel more 'comfortable' now.
The .join did the trick, although I'm not sure to
completely understand it. (After all, I want to 'split'
or 'remove' instead of 'join') but anyway it works.
Need to spend some time reading the manual.

Best regards, Andreu.

Rob Biedenharn wrote:
> That's because the behavior of Array#to_s changed in 1.9. It used to  
> be like Array#join, but now is more like Array#inspect.