ecart display manager STEP 7 images error

Hi guys

look I have spent a couple hours trouble shooting this seemingly simple step but to my ultimate frustration it would appear that it will not work.

Anyway to the specifics.

STEP 7 of the eCart Display Manager tutorial directs you to alter the thumbnail/image placeholder. Seems straightforward enough.

It says double click on the thumbnail placeholder so I double click. I follow the steps (have done it at least 20 times over and over) and entered the info "images/thumbs/" a bunch of different ways, but not once have I been able to get the cart in FFOX or Safari to show the thumbnail.

I hope someone can explain to the me how this simple step isn't working when the snapshot I have attached shows the code is entered exactly right. (I even noticed that when you click on Thumbnail in the Datasource box it uses 'single quotes' not "double quotes" - I tried both and neither worked.)

I even tried copying the exact code from the Music page which was showing it correctly in FFOX and Safari, but even that didn't work?

Please help?