With me, I can't even get through the webpage in  workbench.developerforce.com, it claims my login is incorrect, though it is right.

Admittedly I am using the free account, but it is to help support customers that are paying for the full salesforce service, and my use on salesforce has been plenty light.  If this is a licensing restriction, is there something I can do to be able to use both, or am I doing anything wrong?