SQL Developer

I am on version 1.5.1-5440 of SQL Developer. I am receiving the following error when I try to
login to a database(s) that is on our network. This error does not occur with databases that I
connect to at Oracle On Demand in Austin TX.

String index out of range: 0
Exception Stack Trace:
java.lang.StringIndexOutOfBoundsException: String index out of range: 0
at java.lang.String.charAt(String.java:558)
at oracle.jdbc.driver.PhysicalConnection.setDbTzCalendar(PhysicalConnection.java:4702)
at oracle.jdbc.driver.PhysicalConnection.setSessionTimeZone(PhysicalConnection.java:4657)
at oracle.javatools.db.ora.Oracle8i.initOC(Oracle8i.java:171)
at oracle.javatools.db.ora.Oracle8i.<init>(Oracle8i.java:41)
at oracle.javatools.db.ora.Oracle9i.<init>(Oracle9i.java:181)
at oracle.javatools.db.ora.Oracle9iR2.<init>(Oracle9iR2.java:41)
at oracle.javatools.db.ora.Oracle10g.<init>(Oracle10g.java:26)
at oracle.javatools.db.ora.Oracle10gR2.<init>(Oracle10gR2.java:18)
at oracle.javatools.db.ora.OracleDatabaseFactory.createDatabaseImpl(OracleDatabaseFactory.java:112)
at oracle.javatools.db.DatabaseFactory.createDatabaseImpl(DatabaseFactory.java:147)
at oracle.javatools.db.DatabaseFactory.createDatabase(DatabaseFactory.java:130)
at oracle.jdeveloper.db.DatabaseConnections.getDatabase(DatabaseConnections.java:637)
at oracle.jdeveloper.db.DatabaseConnections.getDatabase(DatabaseConnections.java:564)
at oracle.dbtools.raptor.utils.Connections$ConnectionInfo$ConnectRunnable.doWork(Connections.java:1144)
at oracle.ide.dialogs.ProgressRunnable.run(ProgressRunnable.java:161)
at oracle.ide.dialogs.ProgressBar.run(ProgressBar.java:615)
at java.lang.Thread.run(Thread.java:595)

I have reset my NLS Parameters to their Default Values under the Preferences menu.

Any help short of re-installing would be greatly appreciated.

Thanks,
Raoul