This bug was originally marked as duplicate of bug 168900, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE 7.2 Beta (Build 201205031832)
VM: Java HotSpot(TM) Client VM, 22.0-b10, Java(TM) SE Runtime Environment, 1.7.0_02-b13
OS: Windows 7
GUEST: programin java app
Maximum slowness yet reported was 3119 ms, average is 3119
Created attachment 122959 [details]
As can be seen from the attached snapshot, AWT EDT waits for an extremely slow class loading.