SQL Developer

I'm getting the following error when trying to connect to an Sybase IQ 12.6 database using Oracle's SQL Developer on Windows XP. The database comes with the sun solaris 10 , according to their documentation. I'm running the Oracle SQL Developer, v1.5.0.54.40

When I test the conntivity that was sucess, but when i'm trying to retrive database , I get error 110: "item 'jtds000001' already exists". as well as wnen i try to connect to the database i'm getting following exception

java.lang.NullPointerException
at oracle.javatools.db.JdbcDatabaseImpl.registerBuilders(JdbcDatabaseImpl.java:109)
at oracle.javatools.db.AbstractDatabase.<init>(AbstractDatabase.java:78)
at oracle.javatools.db.JdbcDatabaseImpl.<init>(JdbcDatabaseImpl.java:69)
at oracle.javatools.db.sybase.AdaptiveServerDatabaseImpl.<init>(AdaptiveServerDatabaseImpl.java:106)
at oracle.javatools.db.sybase.AdaptiveServerAnywhereDatabaseImpl.<init>(AdaptiveServerAnywhereDatabaseImpl.java:150)
at oracle.javatools.db.sybase.AdaptiveServerDatabaseFactory.createDatabaseImpl(AdaptiveServerDatabaseFactory.java:39)
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)

Does anyone know what I am doing wrong or how to correct the error?