multiple NID values into an argument

I use :
Views 6.x-3.x-dev (2011-juill.-20)
Apache Solr Views 6.x-1.x-dev (2011-févr.-25)
OpenLayers 6.x-2.0-beta1.

I try to pass multiple NID values into an argument.
Problem, only the first argument works
In my view, I enable:
- 'Validator Options' at 'Validator' choose 'Node'
- 'Argument Type' select 'Node IDs separated by , or +'
- 'Allow Multiple Terms per Argument'

I use this url : myview?nid=55+12