bestseller module problem

I have a demo of OpenCart v1.2.9 I'm testing and having some weird things going on with the Bestseller Module.

The default install sets the limit to 5. I can order five products but only 1 will show.
I can set the limit to show say 7 all 5 products will show. If I then reset the limit to 5 again only 1 will show. There were other limit number settings that didn't let the set limit to show, unfortunately I didn't write them down and haven't tested all possible settings but something isn't quite right here.

Now regardless of the limit set other than 1 or 5 as they only show 1, when a new product is purchased the module is not updating with the new products unless I go into admin and save a new limit setting, like 8 then all five products will show but if I add a 6th product the module isn't updating.

I'm not getting any errors as if fopen isn't working properly. And with each new limit setting a new cache file is created which I'm sure is normal.

Ideas...??

Have you more language files installed?
In which language is your shop setting?

Only English language installed