USB Ports

Problem:
My mother's computer has 4 USB ports on the back, from the mobo and 2 on the front, from the case. When it comes to plugging hardware in, keyboard, mouse, printer, etc. It almost appears that you have to plug into the USB ports in a specific order for them to work.
For example, the keyboard has to be plugged into the top right for it to work, if you plug it into any other USB port it won't register.
Her ipod usb cord will only register if connected to one of the 2 front case usb ports.
Now this is the weirdest part of all. For over a year the keyboard was plugged into one of the USB ports on the back of the computer and one day, she went to turn on the computer and the Keyboard wouldn't register. It has to be plugged into the top USB port on the case for it to register. It is the only USB port on the computer that will allow the keyboard to work.

Any ideas?

this things happen sometimes. it has more to do with the operating system than with the hardware. I guess u are using XP, i had some problems like that on my old xp system.
if u wanna use different usb ports, first turn off the system, re-order the ports like u want to, then turn the system on. should be no problems.

Does not matter if the hardware is plugged in while the computer is on or off. If the keyboard is not plugged into the top front usb port, it will not register at all. Yes the system has Windows XP. It's an older computer, I built it myself, but I never had this problem when I used the computer.