Powerconnect 5324 needs a reset before it boots

Hi Everybody,

I've got a 5324 gigabit switch that is working fine. The only problem is that when i first power it on, it doesn't start on it's own. I need to push the small reset button about 3 tot 5 times quickly. After that I immediatly see it booting on the console and everything is fine, until it looses power again....

I have uploaded a new boot code and software image, but with no result. Does someone know what else i can try?