There isn't a problem. I created a USB stick with unetbootin from the Salix live XFCE iso image. When I clicked on the installer icon after booting from the USB stick, nothing happened.
I ran the command /usr/sbin/salix-live-installer.py in a terminal, which gave me an output indicating that the installer couldn't find the USB stick.
I mounted the USB stick where the installer was looking for it and the installer found it and installed Salix XFCE on my hard drive.
The old slackware type installer that I used last time I installed Salix had a similar method of finding the USB stick to install from.
http://www.salixos.org/wiki/index.php/Install_from_a_USB_stick