This bug was originally marked as duplicate of bug 180230, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE 7.3 (Build 201302132200)
VM: Java HotSpot(TM) 64-Bit Server VM, 23.7-b01, Java(TM) SE Runtime Environment, 1.7.0_15-b03
OS: Windows 7
Maximum slowness yet reported was 60351 ms, average is 60351
Created attachment 131974 [details]
As can be seen from the attached profiler snapshots, AWT EDT is waiting for an extremely slow class loading. Closing as WONTFIX on NB side.