FreeBSD 7 64 bits kernel crash debugging

[Fernando Apesteguía]

Hi all,

I'm experiencing several kernel crashes with the GENERIC kernel and
with custom kernels as well. One of my MP3 players seems to be
recognized, but if I disconnect it from the USB port (even without
mounting the device), I got a kernel crash.

I've tried to follow the instructions at
http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html
I have dumpdev and dumpdir properly set to my swap partition (ad0s2b)
and to /var/crash.

However, during the next boot, I got a message that indicates it is
looking for a dump on such device but it couldn't find any.

How can I track this error?

Thanks in advance.