Hello again!
Thanks for your reply Robert! I really appreciate it.
I tried with both drivers, generic and OEM specific for my model. I installed a fresh Windows 7 Ultimate with all security updates, and before install any other drivers or specific sofware i made a image of entire disk. After failing with generic latest driver (3517) i restored the image and install latest OEM specific drivers (3347 link below), and after wake up several times from sleep (without AC plugged) the issue still present. Every firmware from other components and bios is up to date.
I don´t know if i must open an RMA and return the laptop, but i know that this is coming from software drivers, in Linux never happens and i use it a lot.
For reference, those are the files modified by OEM:
[IMG]http://i.imgur.com/HckczOy.jpg[/IMG]
Link to OEM drivers:
Drivers & software for HP EliteBook 8460p Notebook PC - HP Support Center