I understand now and i’m able to reproduce this, but not the last part (jumping on top of other programs, or stealing focus from them). I have filed a ticket [SPARK-1606] Private message in MUC takes over tab focus and brings chat window up - Jive Software Open Source
But as there are no Spark developers currently, can’t say when and whether it will be fixed.
On the last part though, are you using the 2.7.0 installer with Java included? Maybe you have Java 6 installed on the system? Bring windows to front is not enabled in Spark? Focus stealing bug was related to Java 6 bug and it still was affecting new Spark version if Java 6 was present on the system.