J2SE Version (please include all output from java -version flag):
JDK 7
/Library/Java/JavaVirtualMachines/JDK\ 1.7.0\ Developer\ Preview.jdk/Contents/Home/bin/java -version openjdk version "1.7.0-ea"
OpenJDK Runtime Environment (build 1.7.0-ea-b215) OpenJDK 64-Bit Server VM (build 21.0-b17, mixed mode)


Does this problem occur on J2SE 1.4.x, 1.5 or 6? Yes / No (pick one)
Yes

Operating System Configuration Information (be specific):

OSX 1.7.2


Bug Description:

Preferences implementation of OSX generates a deadlock

Step to reproduce:

The Preferences implementation of OSX generates a deadlock when
simultaneously accessing User- and Systempreferences.

This is an error that persisted throughout older versions of Java for MacOSX
and is still valid on Java 1.7.

Please find attached a test-class and a textfile with output it generates.
You may have to run the class several times.