Very bad, the 100% CPU utilization is suspect as If I recall, not even on PIO mode you get 100% utilization at lowest speed test. For good DMA it is ~10%, not sure.
Burstrate of 0, hmmm, as if the USB link is clogged and not moving data.
Do you have other USB devices and they work fine (actually mouse is very slow device so not a good indication)
Something is wrong with the USB setup either in Windows driver and device manager, or the controller on the motherboard, or maybe you have another USB port or can borrow PCMCIA USB card just for testing, or the cable, that you should replace and try again.
That is assuming you said that on a different laptop the SAME external case with the burner works. Search the forums for problems with external enclusures, some poster experience slowness with certain chipsets and/or firmware, but definately not reading speed of 0.5X
You need to isolate the weakest link.