I have been using a Dell Latitude D600 notebook with Mandriva Linux Free 2006 for a while now. I have an ADSL modem that connects to the computer via an ethernet cable.

A few days ago I began to notice that, for some reason, the network connection to the DSL modem would not always connect using Mandriva's net_applet. Rebooting the computer got it going again. However, earlier today this problem increased into seemingly random crashes (ie. screen freezes), and eventually I got a kernel panic on every boot. So I reinstalled Mandriva.

The crashes haven't gone away. However, I have noticed a pattern: they occur most often when the network status is different to the network cable (ie. up but unplugged or down but plugged-in). The entire system freezes for a few seconds, and then "catches up" with itself, and then freezes again. There doesn't seem to be any way to get out of this cycle, except for pressing the power switch. The freezes sometimes happen at other times; sometimes when plugging the power supply in or taking it out, and a screenlock seems to make it happen sometimes as well.

Any ideas as to what is going wrong, and how I can fix it?

Just tested the wireless network; it crashes in the same way when trying to connect to that as well.