I see two things you might change, but I don't know if they will solve the problem. First, you don't need the "dbtype" attribute anymore with CFQuery, unless it's dbtype="query". Second, it's possible you have a race condition on your query results variable ("data"). You might add a line right below the CFArgument tag:
<cfset var data = "">
This will make the "data" variable local to the function.
Other than that, I can't see anything obvious. I'm not at all versed in WDDX, so maybe someone else will have some better ideas.
Tried that. Did not work. Yep, it is not even running the CFC after the upgrade. Anyone else with ideas on how to fix and get working again?
Is that cfc attempting to do anything with WDDX?