D-Link DIR-825 :: VOIP Behind Router Does Not Work

I have a DIR-825 since a couple of days, Hardware version B1, firmware 2.01EU  (date Fri, 12, Jun, 2009 = latest european firmware) Have portforwarding for ports 25, 80, 443, 143, 993 via virtual server to a local linux server (192.168.0.3)

My (SIP protocol) VOIP phone (192.168.0.100) does not work anymore since I use this router.  It worked fine on my old WRT54G.  The phone logs-in normally at the voip provider but when I make a call, it seems that the ports are not forwarded or are blocked by the firewall.  I have tried to manually setup portforwarding and virtual server instead of portforwarding.

I have tried many things, from disabling QOS, SPI, end point filtering and more but it does not work.  I have also programmed DMZ for my ip-phone, but it does not work. Nothing found in the logfiles about frame drops. (I have setup a syslog on my linux-server)

There seems to be a bug causing frames dropped, as my setup has always worked with my WRT54, and should work with DMZ set, but it does not.  The same setup works fine on a DIR-655 of a friend.