[Plugin: Related Posts Thumbnails] Related posts not always showing on posts

Hi,

My website is: http://www.parfumio.ro/
and it is an e-commerce website using the plugin called WP E-Commerce (WPEC).
It also includes a blog that I have started 3 years ago located here: http://www.parfumio.ro/blog-parfumio/

Congratulations for your excellent plugin! 5 stars from me!
I’ve installed it especially or my blog but I was surprised to find out that it also works for my products and I can use it to recommend other products. Which is great!

But the problem is that it works only on some of my products.
For instance:
– on this product, it works: http://www.parfumio.ro/products-page/oferta-speciala-parfumio/versace-eau-fraiche-masculin-apa-de-toaleta-100ml-3/
– on this one it doesn’t: http://www.parfumio.ro/products-page/hugo-boss-2/hugo-boss-hugo-masculin-apa-de-toaleta-150ml/

I think I discovered the reason but obviously I cannot explain it or solve it.
The product pages defined in WPEC include a field called Additional Description. If that field contains something, the related products DO NOT show.
From the 2 products mentioned above, the second one contains a text “Parfum Hugo Boss Hugo masculin, apa de toaleta 150ml” and that one comes from the Additional Description field. If I delete it, the related products DO show.
I need the Additional Description field to be completed because it contains important information for my products.

Can you suggest a solution so that the related products will show on those pages too?

Thanks
Larry

Can you sug

http://wordpress.org/extend/plugins/related-posts-thumbnails/