This bug was originally marked as duplicate of bug 196813, 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 Beta 2 (Build 201211062253)
VM: Java HotSpot(TM) 64-Bit Server VM, 23.5-b02, Java(TM) SE Runtime Environment, 1.7.0_09-b05
OS: Mac OS X
Maximum slowness yet reported was 4139 ms, average is 4139
Created attachment 127972 [details]
class-loading several UI components, nothing to fix