Email confirmation descriptions are duplicating

Email order confirmations show the description below the product, but the descriptions are "accumulating" and duplicate the ones above it, like this...

1 X 123 = $1.00
This is description for 123
1 X 456 = $1.00
This is description for 123
This is description for 456
1 X 789 = $1.00
This is description for 123
This is description for 456
This is description for 789

Any idea how to fix this? Thanks.

What version of Zen Cart are you using?
What addons/contributions have you installed?
What kinds of customizations have been made to your site?

I have 1.3.7 and I've installed Image Handler, admin permission control, bulk edit, but nothing that would affect order emails. I have done a lot of customization and I'm sure the problem is related to something that I did, but it's been awhile and I just now noticed what it was doing. To be honest I don't know where to look. Any idea about where the problem lies would be very helpful and much appreciated.

It'll be in the order.php class file.

Probably related to the $this->products_ordered variable or failing to reset the $this->products_ordered_attributes variable during the looping through order contents.