Thank you for reporting this, we'll check!
We have a problem with keepVisualState attribute. See https://jira.jboss.org/jira/browse/RF-4566 and https://jira.jboss.org/jira/browse/RF-3651.
But keepVisualState attribute should be used for saving state after submission:"If "true" modalPanel should save state after submission. Default value is "false" (see developer guide). If you want that a modal panel is opened as default, you should use showWhenRendered attribute with "true" value (see developer guide).
If I understand your problem incorrectly, please, send a sample code or sample application.
With showWhenRendered it works. Thanks!