New to burning please help!

I don’t understand why my laptop shuts down when trying to backup a dvd onto my harddrive. Also, I was able to burn okay before the flash. Here is what I am using:
dell 5100 laptop
nec 2500a in a usb2.0 enclosure with firmware 1.07 hv2b4
dvdshrink 3.1 and nero
media: sony dvd+rw 4x

there is maybe something gone wrong when flashing fw, flash back to a previous version try to burn, if it work flash with the new fw again an look what happens.