It was, indeed, created (on Disqus) by the exporter.
I've got flat files, so yay for that.
Okay so here's what I'm noticing:
the one that is able to be exported wrote:[comments] => Array
(
[0] => Array
(
[name] => Jo Michaels
[email] =>
yassbook2012@gmail.com [url] =>
http://jomichaels.blogspot.com [ip] => 74.176.184.75
[useragent] => Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20100101 Firefox/13.0.1
[date] => 2012-06-19-13-47
[comment] => And this is when you hire someone to do your marketing FOR you. There was an interesting post today on Rachelle Gardner's blog about this exact thing:
http://www.rachellegardner.com/2012/06/ ... -building/ You should pop over to her blog and have a gander. She speaks quite forcefully about writers being WRITERS.

WRITE ON!
[registered] => 0
[notify] => 0
[discreet] => 1
[rememberinfo] => 1
[moderate] =>
[spamscore] => 0
)
)
one that doesn't work wrote: [comments] => Array
(
[0] => Array
(
[name] => Jo Michaels
[email] =>
yassbook2012@gmail.com [url] =>
http://jomichaels.blogspot.com [ip] => 74.176.184.75
[useragent] => Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20100101 Firefox/13.0.1
[date] => 2012-06-19-13-48
[comment] => I think getting into the hands of that ONE reader, who will tell ten people, who will tell ten people, and so on and so forth is what we all crave. Really good reviews don't hurt, either

WRITE ON!
[registered] => 0
[notify] => 0
[discreet] => 1
[rememberinfo] => 1
[moderate] =>
[spamscore] => 0
)
Now, apart from the different dates, and the different words in the comment, everything else looks identical.
And yet the top one exports, and the bottom one does not. (Others also look similar, but this one which was posted just one minute AFTER the functioning one, I think is the best case to analyze.
the only thing that looks different is that the top one has an actual URL in its "[comment]" so I tried adding a URL to the bottom one, and it still failed.
I must admit, I am baffled.
Thanks for trying, despite not having time.