Why does the led L lamp blink???

I bought my first Arduino Duemilanove 328 for a few days ago. I followed the install instruction. When it was time to plug the board in the led L blink (irregular) already though I did´nt upload the "first" blink example. The resetbutton seems not to work either. I tried to upload other example (blinkwithoutdelay etc etc). It seems to work for a couple of seconds but then it stop working. When I reset, it starts over again (same loop). Still blinking irregular (led L). Do I have a "broken" board or can I fixed this with some update files? Please help me!

As I understand it you can compile and upload sketches and they work for a while but then stop.

I'm guessing wildly here but check the USB drivers. There's a note in the install instructions of where to look for them. Possibly something is making the serial port reset the board.

You could also try a very simple sketch like Blink and run the board from a battery to eliminate USB interference.

The Led will blink when you reset the board or power it up - just to show it's alive.

This is what is to be expected as a fresh arduino has the random blink sketch already in it.

The resetbutton seems not to work either.

Yes it does it starts the sketch from the start. But as the sketch just blinks the LED you can't see any difference between it going and starting again. You can't stop a sketch it always runs. That's the nature of embedded programs.

I connect a battery eliminator to the board with 9V output. Now it seems to work like I want it to. But still I got problem when it´s connect to the USB. I will try to reinstall everything and add the new FTDI. Do you think this is the problem? Or can it be something else? Thanks for your feedback//