Had the same problem(I guess)
Hi Ramihu,
Just got my 2405FPW the other day and its awesome...
I had the same issues(I guess) as you, the display reset itself every now and then. But reset is not the correct way describing the problem; the display simply faded out, the way OS X does it when it's about to Log Out current user(or similar operations).
That made me a little suspicious because that "symptom" is made purely in software, not by the 2405FPW itself.
So I began twisting the connectors on the 2405FPW side and voila! When I touched the DVI connector, everything froze, mouse, keyboard, the little digital watch in the menubar in Finder. So it simply turned out that it was a problem of the DVI connection, my Gfx board simply lost connection with the 2405FPW and made a soft reset. Tightened the screws on the DVI connector and everything is back to normal.
Hope my description above helps you and good luck!
/Detron