Odd QoQ issue when querying Solr collection

Hello, everyone.

I've got a query of query issue that has me stumped.  Maybe I'm just missing something very simple, but this has got me really confuzzed.

I have a Solr collection that is indexing a few tables in an Oracle database.  Let's call it "hdq", for this discussion.

I wrote a semi-complex query of related tables from which the CFINDEX is using to index the data.  This is working just fine.

I created the Solr collection in the CF9 CFAdmin, and am using the following to index with:

<cfindex action="refresh" collection="hdq" key="QUESTION_ID" type="custom" title="QUESTION_TITLE" query="search_questions" body="QUESTION_TX,QUESTION_TITLE,CATEGORY_NM,TAG_NM,ANSWER_TITLE,ANSWER_TX"

    custom1="QUESTION_STATUS" custom2="TAG_NM" custom3="QUESTION_STATUS" custom4="QUESTION_TYPE" category="CATEGORY_NM">

Then I do a CFSEARCH and name it "hd_questions".  Again, so far, so good, no problems.

If I do a CFDUMP of "hd_questions", one of the columns is KEY (which is QUESTION_ID in the database.)  If I CFOUTPUT the collection, KEY is there.

If I QoQ the CFSEARCH of the collection and use SELECT custom3, score, summary, context, key FROM hd_questions, I get an error message that

Encountered "key. Incorrect Select List, Incorrect select column,

.. then it gives the line number of the page that produced the error, and

<cfquery dbtype="query" name="hd_results">

Am I missing something simple, here?  KEY is in the collection, I can see it in CFDUMP, I can see it in CFOUTPUT.  But if I query the collection and try to select KEY, there is an error.

Any thoughts/ideas?

Thank you,

^_^