I had a strange problem. Any time I unplugged the dsl cable the system froze and would not reboot unless I started Windows, then restarted Linux.
Ubuntu, using kernel 3.2. ** still does this. Fedora, since a few kernel updates ago, not long, has stopped doing this.
I asked everywhere but no one had a solution. Now the culprit has been found:
http://git.kernel.org/?p=linux/kerne...80929a078c0fd5
Just for anyone who may be interested.