Duemilanove doesn't reset after uploading

Hi. My Arduino duemilanove used to reset itself automatically after uploading a sketch. Now, I have to manually press the reset button, or open the serial monitor and then close it, which then resets the board.

Any ideas?

well if opening and closing the serial monitor is resetting it
"software" reset is working (right?)

did you try reinstalling the arduino software?

Thanks for the advice. I reinstalled the current version of the arduino software but still not luck.