I've tried the usb (unetbootin) with several different images. 3 Different version of BT4 and Both the original and R1 (in both KDE and Gnome) of BT5. I haven't tried the low speed, but I've tried the same discs with other machines and they work just fine. In fact I recently used one of them to image an older desktop of mine (older than the laptop) and it worked wonderfully. Will the lower speed cd burning make it easier for the laptop to read the disc? or were you just contemplating a bad burn?