I'm new to this module and not sure if i have just overlooked something or whether it's just that i'm running SS in XAMPP on a windows platform but within the supplied templates you seem to have used quotation marks within quotation marks quite a lot.
the sprintf data within the alt atribute is creating invalid html and causing errors
//product.ss --- line 17
<img class="productImage" src="$Image.ContentImage.URL" alt="<% sprintf(_t("IMAGE","%s image"),$Title) %>" />
<img class="productImage" src="$Image.ContentImage.URL" alt="<% sprintf(_t('IMAGE','%s image'),$Title) %>" />
I have had to go through and change this within every supplied template file (Not the most exciting thing i've had to do today).
To finish on a high point - this seems to be an amazing module. Good work :)