CoD WaW save problems

ok,I've been playing through the campaign on veteran now and I'm nearly finished it,but, whenever I save and quit halfway through a mission and when I restart it I have to start the WHOLE level again which is really **** annoying!

Has anybody else been getting this problem?

U have to select resume level to continue from your last checkpoint. If you play a different mission your previous save is gone.DJSAV_101

That's what I'm doing and it's not working for me

ok,I've been playing through the campaign on veteran now and I'm nearly finished it,but, whenever I save and quit halfway through a mission and when I restart it I have to start the WHOLE level again which is really **** annoying!

Has anybody else been getting this problem?

Frostbite345