Dropping udp packets in xwindows

[tecknophreak]

If I sit back and relax, I don't miss any packets from a multicast.
However, when I maximize, minimize windows or change desktops, I start losing packets. When I stop I receive the packets just fine.

A few details:
RH 8
KDE
UDP speed 12-14 Mbits in packets of 10-40k

I'm assuming this is because the kernel thinks it has better things to do, like help KDE out. I changed the time inbetween packets, it was < 1 ms between for a 5 packet burst, then I put in around 12 ms delay between the packets to give the OS/kernel a little more time to get back to the packets.

I've set up the net.core.w/rmem_max to 8M and the net.core.w/rmem_default to 1 M, so I'm guessing there's enough memory there.

I also need the UDP multicast since I need the data to go to more than 1 machine.

Any Ideas? a setting I should change or something of the sort?
The kernel can't keep up with this when doing things in KDE?

I know KDE is huge on memory and cpu, but I sort of need to use either KDE or GNOME.

[tecknophreak]

Do you think that if I increased the priority on this prog, that might fix it?

I do know that the dropped packets only occur when I do things in X, even move a terminal.