In fact I have the same problem with GNOME battery applets. If I add the battery applet to the panel, I get this error message:
"Can't access ACPI events in /var/run/acpi.socket! Make sure the ACPI subsystem is working and the acpid daemon is running."
And
$ sudo /etc/init.d/acpid start * Loading ACPI modules... [ ok ] * Starting ACPI services... acpid: can't open /proc/acpi/event: Device or resource busy
$ sudo fuser -v /proc/acpi/event
USER PID ACCESS COMMAND /proc/acpi/event: haldaemon 4104 f.... hald-addon-acpi
In fact I have the same problem with GNOME battery applets. If I add the battery applet to the panel, I get this error message:
"Can't access ACPI events in /var/run/ acpi.socket! Make sure the ACPI subsystem is working and the acpid daemon is running."
And
$ sudo /etc/init.d/acpid start
* Loading ACPI modules... [ ok ]
* Starting ACPI services... acpid: can't open /proc/acpi/event: Device or resource busy
$ sudo fuser -v /proc/acpi/event
/proc/acpi/event: haldaemon 4104 f.... hald-addon-acpi