psp and usb port

[chipmunkmike]

just installed the software for the psp. My laptop pc detects when something is insterted into any of the four usb ports, all of which work fine, but for some reason when trying to use the media centre software for the psp it still states 'please connect psp'. I have put the psp in usb mode but this does nothing. I have followed all the instructions in the help section but to no effect. Like I said the pc emits the usual tone when something is connected via the usb but for some reason the media centre software is not recognising it. I have had simila problems in the past with mobile phone software and usb. Can anyone help?
Cheers