HOw's your diet and rest?

Have you tried alternating with Heavy weights one week and light(ish) the next. Again it gives the chest a break without having a complete rest.

Also what weight increments are you using? If you jump in too big a step this often leads to stagnation as you can't do it again the following week.

And where is the sticking point, actually getting it off your chest or further up during the lockout phase.

How is your shoulder and tricep training coming along? as this obviously has a big impact on your benching too.

What other chest exercises do you do?

Heavy weighted dips can be very good to help with tricep and chest strength.

Paul