TOPIC: Very slow Registration pages and Free Entry

Recently, our DT Register web pages have been taking over 30 seconds to display. One of these takes a long time and never displays the registration fee.
The long time to display is mostly spend with a series of 20 pairs of post each of which takes around 2 seconds for the response. The first is:
www.mdchess.com/index.php?option=com_dtr...task=events&Itemid=9
Then there is:
www.mdchess.com/index.php?test=1&no_html..._dtregister&Itemid=9
Which always returns:
<div id="dtfee_display">
</div>
For the events that do get the correct registration fee displayed, the "dtfree_display" instead has the correct fee. But since this pair of requests takes 4 seconds, the page takes around 40 seconds to display.
We're running 3.1.13.
Any idea?
Thanks
Mike Regan

I've been able to make some progress on this. I was able to speed it up by around a factor of three by setting the Joomla error reporting to "default" rather than "none". It still has the 40 or so redundant HTTP Post requests but they only take a half a second rather than two seconds each.
I was able to get the event to correctly calculate the registration fee by deleting the event and creating a new one. It was a lot quicker than all the random things I tried to get it to work.
Mike