Poor dvd picture on lcd tv

I recently purchased a Sony KDL-32D3000 lcd tv. Freeview and Sky picture is great. The problem i have is with my dvd's. Most of them produce an excellent  picture but a few are pretty awful. The new Harry Potter, Zodiac and The Illusionist are 3 culprits. Some times the darker pictures seem a bit wobbly and in The Illusionist faces in shadow seemed as if they were melting. Is it because the tv is 100hz or is it just the nature of lcd? My dvd home cinema is a Panasonic SA-MT1. Any help would be greatly appreciated.