The connection type "EXCEL" specified for connection manager ... is not recognized as a valid connection manager type. This error is returned when an attempt is made to create a connection manager for an unknown connection type. Check the spelling in the connection type name.

I found one suggestion of reinstalling MDAC (right clicking %windir%\inf\mdac.inf->Install). Needed XP CD handy.

Still, the problem persisted. Another suggestion was to allow users or network service access to Lexmark driver registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{0cd637c0-0892-11d4-892f-00008364d903} - That fixed it for me.  Just one more reason to not buy Lexmark ever again.