I've installed Ubuntu on my Macbook before but something went wrong with the updater. So, I had to backup my HDD and format it and reinstall OS X Lion.
But here's the thing: Ever since I re-installed my OS I've been trying to get Ubuntu back on the HDD. I partitioned it to 40 GB and set the file system to Ext4. I also recently created a swap partition too and it seems to install correctly.
After i installed rEFIt it just has this cute little penguin sitting there. I rebooted and tried to go back to Ubuntu and the penguin still shows up but this time a black screen pops up and it asks me to insert a bootable device and press any key. I'm not sure why this is happening.
This is probably the 5th time I've tried to install it. I've even used a different Ubuntu ISO but it still won't boot after the installation.