From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux 2.4.3-12 i686; en-US; 0.7)
Description of problem:
The colortoalpha plug-in cannot be invoked with the RUN_NONINTERACTIVE mode
(i.e. from script-fu). It always fails with a PDB call error.
Steps to Reproduce:
1. Open script-fu console
2. Invoke "(plug-in-colortoalpha RUN-NONINTERACTVE image layer color)"
(image, layer, and color values chosen are unimportant)
3. Watch it fail.
A patch which fixes the problem (against gimp-1.2.2) is attached. I have
also submitted this patch to the plug-in author, but figured (particularly
with the new public beta) I'd let you guys know as well..
Created attachment 27394 [details]
Patcb to fix colortoalpha plug-in RUN_NONINTERACTIVE mode
I guess this should be fixed in current GIMP ;-).