Is this schematic the ISP part of your circuit or just a standalone programmer? (I assume it is just for programming purpose)

In any case:
1) I don't see any decoupling capacitors.
2) Don't leave the unused input of the latch as unconnected.
3) For the time being, remove the pull down resistor (at RST signal from parallel port) and generate RESET from PC. Or relocate the reset capacitor to the resistor side if you need a POR as well. You will need 10uF capacitor with 10K resistor.