Steps to reproduce it,

1) fire frysk,
[qiyao@localhost ~/build-frysk]$ ./frysk-gui/frysk/gui/FryskGui &
[1] 7397
2) click "Debug an Existing Process"
3) Select "bash"
4) In source window -> View -> Register Window
An Npe could be got, and frysk will exit for a while.

[qiyao@localhost ~/build-frysk]$ blocking
null
java.lang.NullPointerException
   at org.gnu.gtk.Gtk.gtk_main(libgtkjava-2.8.so)
   at org.gnu.gtk.Gtk.main(libgtkjava-2.8.so)
   at frysk.gui.Gui.gui(FryskGui)
   at frysk.gui.FryskGui.main(FryskGui)


Phil, assign this bug to you, :)

Information about this box,

[qiyao@localhost ~/build-frysk]$ uname -a
Linux localhost.localdomain 2.6.17-1.2630.fc6 #1 SMP Wed Sep 6 17:17:26 EDT 2006
ppc64 ppc64 ppc64 GNU/Linux
[qiyao@localhost ~/build-frysk]$ gcj -v
Using built-in specs.
Reading specs from /usr/lib/gcc/ppc64-redhat-linux/4.1.1/libgcj.spec
rename spec startfile to startfileorig
rename spec lib to liborig
Target: ppc64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-libgcj-multifile
--enable-languages=c,c++,objc,obj-c++,java,fortran --enable-java-awt=gtk
--disable-dssi --enable-plugin
--with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --enable-secureplt
--with-long-double-128 --host=ppc64-redhat-linux --build=ppc64-redhat-linux
--target=ppc64-redhat-linux --with-cpu=default32
Thread model: posix
gcc version 4.1.1 20060828 (Red Hat 4.1.1-20)