Index: trunk/src_plugins/cam/cam_compile.c
===================================================================
--- trunk/src_plugins/cam/cam_compile.c	(revision 27413)
+++ trunk/src_plugins/cam/cam_compile.c	(revision 27414)
@@ -95,6 +95,8 @@
 			argv = ctx->argv;
 			if (ctx->exporter->parse_arguments(ctx->exporter, &argc, &argv) != 0) {
 				pcb_message(PCB_MSG_ERROR, "cam: exporter '%s' refused the arguments\n", code->op.write.arg);
+				ctx->argv[0] = NULL;
+				ctx->argv[1] = NULL;
 				return -1;
 			}