usb devices starts only if asus a4s is warmed

My Asus a4s (Pentium IV 630) at bios time not start usb devices
(mouse, usb wireless, etc...).

For example, at start of bios, mouse led would be light, instead it
become light only after this procedure is done:

1) Computer is turned on without mouse plugged (If not windows startup
become blocked until all usb device are removed - Linux go at finish
but usb devices cannot be used)
2) Wait 10/15 minutes that computer is turned on.
3) Shutdown of Windows or Linux. (Attention: shutdown and not restart)
4) Turn on computer with mouse and usb devices plugged.
5) Now mouse led is lighted and all usb devices can be used.

How it's possible? Can be motherbord or battery?