Took 3 because on the first two burns the md5sums didn't match.
I'm cross ways of you there ... no grubs, only lilo. And burn in CLI:
Code:
cdrecord driveropts=burnfree -overburn -v -dev=/dev/sr0 nFluxOS-UMM-i686.iso
Did not use burnfree or overburn the first two times, but can't say that was it.
The ISO md5sum and your published one checked out ... I only use
aria2 for d/l if possible, and it prevents bad d/ls.