How does One Touch Mini Compairs to Contour usb Meter?

Hey guys, I have always used One Touch Meters..but my brother has gotten me a Contour USB Meter to use because " it is up to date". I just used the meter and I have found that the BG rate is very off. I tested at 9.3 and then I used my Mini and it said 12.3, Which one is correct? I like the idea of the USB part but if it is going to be giving flase readings...what should I do?