Our NetBeans customers reported this issue, see http://www.netbeans.org/issues/show_bug.cgi?id=108138
Steps to reproduce:

1) Change OS file preferences to show hidden files/folders.
(On my Linux Ubuntu 7.04 - go to main menu System -> Preferences -> File Management, enable "Show hidden and backup files" on Views tab.)

2) Open SwingSet2 demo, choose JFileChooser demo, plain JFileChooser

bug: hidden folders and files are not visible inside JFileChosser, but they should be according to OS settings.

Note that this bug is Unix specific, perhaps even GTK L&F specific. On Windows everything works just fine.