Magento

When I put a extension key in the connect manager I get the following Error, what is the problem please any help would be appretiated.
I got one Extension Installed then this problem started
Thanks

THIS IS THE PROBLEM:
Failed to download magento-community/Mage_Imaclean within preferred state “stable”, latest release is version 0.1.0, stability “beta”, use “channel://connect.magentocommerce.com/community/Mage_Imaclean-0.1.0” to install
Cannot initialize ‘channel://connect.magentocommerce.com/community/Mage_Imaclean’, invalid or missing package file
Install Errors
Package “channel://connect.magentocommerce.com/community/Mage_Imaclean” is not valid
PEAR ERROR: install failed

You have to set your preferred state to beta in the Magento Connect options in order to download an extension labeled as beta.