are you sure you boot in x32 mode ?
you have to add arch=i386 flag to boot plist
this is what my plist look:
CODE
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Flags</key>
<string>arch=i386</string>
<key>Default Partition</key>
<string>hd(2,2)</string>
<key>Timeout</key>
<string>5</string>
<key>GraphicsEnabler</key>
<string>yes</string>
<key>Graphics Mode</key>
<string>1280x800x32@60</string>
<key>EthernetBuiltIn</key>
<string>yes</string>
</dict>
</plist>