Alpine-xen liveCD from USB

I was attempting to run the Alpine LiveCD from a USB stick, and am having some problems with the syslinux setup. I used UNETBOOTIN to write the image (alpine-xen-2.6.3-x86_64.iso), and it fails to boot. syslinux loads up, but reports that mboot.c32 is not a valid COM32 file. I have seen errors like this before, and it usually has to do with the syslinux kernel being a different version than the c32 files. So, what version of syslinux is the livecd built with? I'm thinking the problem is it is different than that bundled with unetbootin (which I think reports as 4.03).