I have changed before mentioned parameters, but it did not help. Recently we have replaced our old Dell with new one - Powerconnect 6248, updated firmware to 3.3.1.10 and now all these PING problems has gone!
Hello!  Is there any way to give a higher priority to ICMP echo request on Powerconnect 6224 interface?  The problem is that we use Powerconnect for routing and also we are monitoring it with monitoring software. Sometimes it does not respond to PING although as a rooter it works fine. Host behind the Powerconnect responses always. So it means that interface on Powerconnect itself sometimes drops ICMP echo request and it gives false positive to our monitoring application.
ICMP echo request on Powerconnect 6224 interface