I've been using the minimal image Scott Ellis detailed here:
http://www.jumpnowtek.com/index.php?option=com_content&view=article&id=65:gumstix-quick-boot&catid=35:gumstix&Itemid=67

However, I'm only seeing 128MB of RAM rather than the 256MB I know the Overo Earth has. Other images make use of the full RAM size.

Can this be fixed simply? Is it a kernel config setting gone wrong?