problem with installation

[mkiing]

hi
i have a problem with my installation. i made everything like in the description. i have a macbook and the ubuntu i put on a stick. then i booted from the stick and everything worked but then when i want to install ubuntu, i press enter, but nothing is working. it shows that the installation needs a few minutes but after 2 hours nothing happened.

i tried it with 12.10 desktop ubuntu...

please help me ;)