Page 1 of fox disc problems

purchased 3 fox dvds from asda a good few months back:
thin red line
the seige
chain reaction
been very busy so didnot play them until yesterday and got probs.
the seige and chain reaction play fine for first 50 mins then
you cant see a clear picture all squares and sound goes.
all other dvds i own work fine just these 2 has anyone else had
same problems.

thx

What player do you have?
Different players have different problems!