The present invention includes a surgical stapler having a staple cartridge, an anvil, a cutting member having a cutting surface, and a driver operably engaged with the cutting member to move the cutting member relative to the anvil and the staple cartridge. In at least one embodiment, one of the anvil and the staple cartridge defines a slot which is configured to receive at least a portion of the cutting member and guide the cutting member as it is moved relative to the anvil and the staple cartridge. In these embodiments, the slot can also be configured to receive a portion of the driver operably engaged with cutting member and support the driver when it moves the cutting member. In at least one embodiment, the slot is defined by at least one radius of curvature.