Have looked at your file and it does not match the download
size. K3B says that the download is a 1.4Gb file but the actual length
of what you recorded is only 279.2 Megabytes.

Looks like you have suffered the same as me, a time out somewhere along
the way. To save wasting disks, save your download and do not try to
burn until you have the full file - do a checksum to be sure of it.