Booting in using USB stick on MacBook Pro

I’ve installed Haiku on a 2GB Kingston USB stick. I hold down the Option key at boot-up but my MacBook Pro just won’t spot the USB stick. Any help appreciated.

there are some problems with some Kingston USB stick.
see:
http://dev.haiku-os.org/ticket/4135

Did you try any other USB stick ?

Thanks very much for pointing that out. I’ll try another stick. Cheers