can't install with usb pen drive, SYSLINUX problem
In 10.10 there is a bug in usb-creator that may cause your problems. Try creating your stick using UNetbootin, as was just suggested.
There are reports that you can fix the bug by opening syslinux.cfg on the USB drive and replace the following line:
ui gfxboot bootlogo
with
gfxboot bootlogo
Okay, the problem is that you didn't format your USB to FAT32.
You could try using UNetbootin, another tool for the same purpose of making bootable usb drives. It's in the repositories as unetbootin.