Has anyone seen this error before

This error means that a script requires persistent and high number of sql connections. OSCommerce and some other Php applications are very well known to produce/cause such a problem. You'll need to do the following: restart the MySQL service to clear out the connections, disable the application and/or increase the number of connections in the conf file. For example, in OSCommerce config file change from true to false:

before
define('USE_PCONNECT', 'true');
after
define('USE_PCONNECT', 'false');

If you're dealing with a different application, just see if you can modify the "connection" in the conf file.