USB port not recognizing any device

Hi again Bodhi,
i come now with a new challenge :D

after all our surgery to my PPv4, everything seems to go normal now, i managed to install Optware/samba and it works perfect, however, for an unknown reason, theres one of the rear usb ports that is not working. I have tried connecting different devices and none of them is being recognized not using the web acces or even through console. I did some testing again connecting the serial cable and in any other port it automatically recognizes and starts booting the harddrive but in that specific one, it doesn't even throws an error message.

Have you ever got into one similar case? could you help me out on this?

any advice again will be well received!!

thanks again in advance.