java problem from attempt to use j interpreter

Debian users, I've installed a J interpreter which works OK from the command line. The Java based GUI yields this report. Any ideas? Thanks, ... Peter Easthope [EMAIL PROTECTED]:~/j601$ ./jw java.lang.ClassCastException: java.awt.DefaultFocusTraversalPolicy cannot be cast to javax.swi

java problem from attempt to use j interpreter

[EMAIL PROTECTED]:~/j601$ ./jw java.lang.ClassCastException: java.awt.DefaultFocusTraversalPolicy cannot be cast to javax.swing. CompatibilityFocusTraversalPolicy at javax.swing.JComponent.setNextFocusableComponent(libgcj.so.70) at jx.utils.wcc.wccx(Unknown Source) at jx.utils.wd0.wdexec(U