package acpid 1.0.6-9ubuntu4.9.04.2 failed to install/upgrade: sub-processo post-installation script retornou estado de saída de erro 1

[Bremm]

Binary package hint: acpid

Configurando acpid (1.0.6-9ubuntu4.9.04.2) ...
 * Stopping Hardware abstraction layer hald [ OK ]
 * Loading ACPI modules... [ OK ]
 * Starting ACPI services... acpid: can't open /proc/acpi/event: Device or resource busy
invoke-rc.d: initscript acpid, action "start" failed.
dpkg: erro processando acpid (--configure):
 sub-processo post-installation script retornou estado de saída de erro 1

No idea about why it happened.

ProblemType: Package
Architecture: amd64
DistroRelease: Ubuntu 9.04
ErrorMessage: sub-processo post-installation script retornou estado de saída de erro 1
NonfreeKernelModules: nvidia
Package: acpid 1.0.6-9ubuntu4.9.04.2
SourcePackage: acpid
Title: package acpid 1.0.6-9ubuntu4.9.04.2 failed to install/upgrade: sub-processo post-installation script retornou estado de saída de erro 1
Uname: Linux 2.6.28-3-rt x86_64

[Bremm (bremm)]

$ LANG=C sudo cat /proc/acpi/event
cat: /proc/acpi/event: Device or resource busy