A DESCRIPTION OF THE PROBLEM :
The documentation is confusing, because it says the method returned the Look and Feels "that have been installed with this software development kit". It looks like the array was taken from the SDK at compile time, rather than from the executing JRE.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Returns an array of objects that provide some information about the LookAndFeel implementations that have been installed with this runtime environment. The LookAndFeel info objects can used by an application to construct a menu of look and feel options for the user or to set the look and feel at start up time. Note that we do not return the LookAndFeel classes themselves here to avoid the cost of unnecessarily loading them.
ACTUAL -
Returns an array of objects that provide some information about the LookAndFeel implementations that have been installed with this software development kit. The LookAndFeel info objects can used by an application to construct a menu of look and feel options for the user or to set the look and feel at start up time. Note that we do not return the LookAndFeel classes themselves here to avoid the cost of unnecessarily loading them.

URL OF FAULTY DOCUMENTATION :
http://java.sun.com/j2se/1.5.0/docs/api/javax/swing/UIManager.html#getInstalledLookAndFeels()