Nah, the antiX installer is an installer on it's own (it might be based on the Mepis installer, perhaps it is the same one, but it ain't a modified refracta installer).
I think.
I think the OP is already answered here:
http://antix.freeforums.org/viewtopic.php?f=49&t=4426I tried it like this:
I installed antix to VirtualBox.
I discovered that the installer was gone (minstall?)
I booted an antiX live and copied the executable (minstall?) to the installed version.
When i ran it after rebooting the installer failed.
Then i went to bed. Next day i read anticapitalista's answer and decided that the problem is better solved by other people than me.