I agree that, and not just by researchers, the two are confused but then is the use of data and information not also heavily confused?
The statement that KM is nonsense, and again I agree, is also equally applicable to Information Management. If information is a human attribute, (computers do not give us information, information is by interpretation of 'capta' obtained from the presented data) then communication is a data-stream that needs to be interpreted in the given context before it can become information.
Checkland and Holwell (1998) Information, Systems and Information Systems. Here they put forward an argument on the need for a conceptual cleansing of Information Systems and the semantic pollution and abuse of terminology within IS.
To me, knowledge is long term, retained information and as you mention it is personal. Wisdom, and I not so clear on this one, is the sharing of knowledge, in a useful context, with others. Thus knowledge is inbound and wisdom is outbound. You can declare yourself knowledgeable but it is only others that can declare you wise.
Data -- Capta -- Information -- Knowledge -- Wisdom
Given -- Taken -- Interpretation -- Taken -- Given