Tested with the following environment:
* Product Version: NetBeans IDE Dev (Build 200807101204)
* Java: 1.6.0_10-beta; Java HotSpot(TM) Client VM 11.0-b11
* System: Linux version 2.6.24-19-generic running on i386; UTF-8; en_US (nb)
* Userdir: /home/josin/.netbeans/dev

There is no accessible description and mnemonic for "Enable Quick Run" CheckBox.
(Project Properties > Run)

Full output accessibility tester:
=========================================== 
Tested Window title : Project Properties - JavaApplication2?
===========================================

Doesn't implement Accessible : - none.

No Accessible name : - none.

No Accessible description :

Class
    javax.swing.JCheckBox { Enable Quick Run | } 

Label with LABEL_FOR not set : - none.

Components with no LABEL_FOR pointing to it :

Class
    org.openide.explorer.view.TreeView$ExplorerTree { Properties Category | N/A } 

Components with no mnemonic :

Class
    javax.swing.JCheckBox { Enable Quick Run | } 
Class
    javax.swing.JLabel { (e.g. -Xms10m) | (e.g. -Xms10m) } 

Components with wrong mnemonic (mnemonic isn't ASCII , label doesn't contain mnemonic): - none.

Components not reachable with tab traversal : - none. [Evaluation: