You can use view-scoped or form-scoped a4j:queue component to make requests run sequentially. a4j:queue is available since 3.3.0.GA. I've added task: https://jira.jboss.org/jira/browse/RF-6458 for addition of queuing attributes to sorting and filtering.
Thanks for your fast reply. Yes a4j:queue would help. But I can use this not before 3.3.1 or RF-6458, right?
What about extending rich:column with data processing options like ajaxSingle to drop submitted values? -> https://jira.jboss.org/jira/browse/RF-6450
You can use a4j:queue in 3.3.0. And I think we'll resolve the issue soon.