Try to change:
to
Code:
fputs($socket,"POST /frontend/".$skin."/backup/dofullbackup.html?".$params." HTTP/1.0\r\n");
to:
Code:
fputs($socket,"POST /frontend/".$skin."/backup/wizard-fullbackup.html?".$params." HTTP/1.0\r\n");
The parameters might have to be edited as well, but I have to get to class. I'll try to look at it some more later.