Hi,

A recent change in gdb has rendered a function invisible to insight, so 
I've found a suitable replacement and committed the attached patch.

Keith

ChangeLog
2008-04-21  Keith Seitz  <keiths@redhat.com>

         * generic/gdbtk-cmds.c (symtab_to_filename): Call gdb's
         open_source_file instead of find_and_open_source.