Can't upload sketches to my homemade arduino

Hi,

I made this arduino for a school project but I can't get it to work. In fact I can't upload sketches into.
That's what I have:

• Arduino serial2USB light adapter ( http://arduino.cc/en/Main/USBSerial)
• My custom arduino PCB
• Arduino 1.0.5

What I'm trying to do:
I'm trying to upload a sketch on it using Arduino IDE and Arduino's Serial2USB Light Adapter.

Error I get on Arduino IDE
avrdude: stk500_getsync(): not in sync: resp=0x00

Notes

• Drivers are installed correctly and COM is successfully set.
• ATMEGA 328P-PN is already programmed with Optiboot
• When I press Reset button nothing happens.

SERIAL- PCB CONNECTIONS
5V- 5V
GND-GND
TX-RX
RX-TX
RESET/EXT- DTR

PCB SCHEMATICS

If you need further informations please ask
Thank you for your help

(deleted)

thanks. What should I do to fix this error?

(deleted)

so there's a problem with reset button? I don't understand

(deleted)

sorry, I'm not an electronic and I don't understand what should I do

Could you explain me ?
Thank you

I'm using a jumper to connect DTR to RESET pin and ATMEGA 1st PIN (RESET).
I've also used a capacitor and a 10kOhm res.

What is wrong?
(see first image on first post )

Found a fix! There was a connection problem with OSC.
Here's the solution (many thanks to Christian Aschoff of Fritzing forum):

http://fritzing.org/forum/thread/3394/?page=last