Topic: Server hungs running chilli

I'm using chilli + radius to restrict access to my network. This server hungs regularly about once per week. Some times it works longer sometimes shorter. I had similar problem running chilli on WRT54G  with OpenWRT and chilli. I've changed this configuration to server because I thought that this is because low memory and slow processor of WRT54G but problem still exists on server. (Server was changed too smile )
I have about 15 network users. Some of them use mac addres login, some of them login through UAM page.

When server hangs it is totally dead.
What can I do or what I have to change to make it stable? Is it a chilli problem? Has any similar problem to this?

There is no logs or other things (even on screen which is black when it hangs) to help diagnose problem.

Thanks for any help.