This bug was originally marked as duplicate of bug 177275, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE 7.1 Beta (Build 201109252201)
VM: Java HotSpot(TM) 64-Bit Server VM, 21.0-b17, Java(TM) SE Runtime Environment, 1.7.0-b147
OS: Windows 7
rptmaestro: Trying to get element code completion in FXML
Maximum slowness yet reported was 22293 ms, average is 22293
Created attachment 111442 [details]
Profiler Snapshot shows that internet connection was delayed by your proxy or something? while editting an XML document which did not have local schema.