The Product Groups .NET plug-in in thumbnail mode does an AJAX reload of the products when navigating between "pages" of results, rather than reloading the entire web page.
If you are at the bottom of a long list of thumbnails, the reload doesn't take you to the top of the page causing users to have to scroll up on ever page they navigate through.
This is a very tidious point that annoys a lot of staff in the office also, as we use the FE when working with customers over the phone. It can be easy for customers to miss products if they are only at the top of the next page.