I had a customer last week report he applied hot fix 64430 to CFMX 7.0.2 and started getting variable undefined errors for queryname.recordCount for empty Informix record sets. I confirmed the debug output shows a valid query with recordcount=0; but CF throws undefined variable/object errors if you try to output any of the query variables (recordCount, currentRow, or columnList).
This issue occurred when using the IBM Informix v2.11 drivers with CFMX 7.0.2 hf702_64430. It does not occur when using the IBM Informix v3.0 drivers or the bundled DataDirect Informix driver.
I created technote 8704413c for this issue which should be published shortly. See technote tn_19171 for instructions on configuring the IBM JDBC driver.