This bug was originally marked as duplicate of bug 181584, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE 8.0.2 (Build 201411181905)
VM: Java HotSpot(TM) 64-Bit Server VM, 25.45-b02, Java(TM) SE Runtime Environment, 1.8.0_45-b14
OS: Windows 8
GUEST: SLOW SLOW SLOW SLOW
Maximum slowness yet reported was 27152 ms, average is 27152
Created attachment 156304 [details]
Seems like a JDK problem. 17s spent in single call to javax.swing.PopupFactory$HeavyWeightPopup.hide()