Error message when one field is left empty.

Hi,

I have been playing with modifying the existing blog template to suit my own needs. I seem to have broken something. When I leave a field empty, I get the following error:

Warning: Invalid argument supplied for foreach() in /home/mysite/public_html/components/com_flexicontent/templates/people/item.php on line 197

Line 197 is as follows:
<?php foreach ($this->item->positions as $field) : ?>

You can see this error in action on my site: deadcanadians.ca/index.php?optio ... &Itemid=83


Here is an example using the same template that includes data in the "Web references" field:
deadcanadians.ca/index.php?optio ... &Itemid=83

Thanks,

Stephanie