Page 1 of Dodgy menus on rental DVDs

Recently bought a Wharefdale DVD player.

First file I bought was MI:2. Played fine, able to access all the other stuff fine.

Since then I`ve watched two rental films - Supernova and You`re Dead. Films played fine, but had trouble using some of the menus to access things like deleted scenes etc.

It just seemed that, in one case, the menu did`nt work at all, in the other, it was impossible to select a menu option correctly.

I did get around this by working it out and using the GOTO function to go to the title and chapter directly. I was then able to watch these extra bits but of course its a bit of a pain.

Could it be due to the fact that the rented DVDs were`nt in A1 condition ? Any ideas at all ?