AVR-Chat

Folks, i have a really bit problem i cant understand.
I am using ATMEGA32L on a 7805 powered board but i cant make it run 
or even reset. The chip is proprerly powered , i tried a lot of reset 
circuits, of course including the one provided by atmel, but there is 
no way it runs by itself. The thing comes when a tie an external 
voltage source to the reset pin (ex. an ISP programmer). Everything 
seems to work fine, even the reset circuitry, but as soon as i take 
out this external reset source, the chip halts. I dont have a clue 
about what this could be. I am using internal clock source and tried 
1 and 8 MHZ. 
Ever happenned to you?? Suggestions??? ANY CLUEEEE!??????


Thanks 
Javier