While doing some development on the Meanbee postcode module today on Magento 1.4.0.1, I received the following error:

There has been an error processing your request

Exception printing is disabled by default for security reasons.

Error log record number: 1037788671028

It takes 2 seconds to enable this. Go to the magento installation root and then into the errors folder. Subsequently:

cp local.xml.sample local.xml 

Exception printing is now enabled.