--- acpi-1.4/acpi.c.orig	2009-03-23 17:23:12 +0200

+++ acpi-1.4/acpi.c	2009-07-03 10:32:27 +0300

@@ -303,6 +303,8 @@

 		state = value->value;

 	    } else if (!strcmp(value->attr, "voltage_now")) {

 		voltage = get_unit_value(value->value) / 1000;

+			if (!voltage) /* zero voltage makes all calculations mood */

+				voltage = -1;

 	    }

 	    fields = list_next(fields);

 	}