Description of problem:
When clicking OK button on material edit window, a dialog saying
"wpc_pov:dialog/2: crashed" is displayed, the material edit window is not closed
and changes are not saved.

Version-Release number of selected component (if applicable):
wings-0:0.98.32b-9.fc6.i386

How reproducible:
Everytime.

Steps to Reproduce:
1. Start Wings.
2. Open the outliner window (from menu Window->Outliner).
3. Choose material "default", right click on it and choose edit.
4. Click OK.
  
Actual results:
The material edit window does not close and an error message is displayed.

Expected results:
The material edit window should close and the changes to the material should be
saved.

Additional info:
When run from commandline, the output looks like this:
$ rm -rf $HOME/.wings ; wings
Trying OpenGL modes
  [{buffer_size,32},{depth_size,32},{stencil_size,8},{accum_size,16}]
  [{buffer_size,24},{depth_size,32},{stencil_size,8},{accum_size,16}]
  [{buffer_size,24},{depth_size,24},{stencil_size,8},{accum_size,16}]
Actual: RGBA: 8 8 8 0 Depth: 24 Stencil: 8 Accum: 16 16 16 16
wpc_pov:dialog/2: crashed: {error,[{kayos_utils,
                                       split_list,
                                       [[{material_editor_ok,true}],45]},
                                   {pov_ui,material_result,3},
                                   {wings_plugin,dialog_result1,3},
                                   {wings_material,plugin_results,3},
                                   {wings_material,'-edit_dialog/4-fun-1-',6},
                                   {wings_ask,return_result,1},
                                   {wings_wm,handle_event,3},
                                   {wings_wm,send_event,2}]}