HI all,
            this happend creating a new a lv with the command lvcreate 
-L512M -ntest system
It did 3 times in a row then it worked again. What was strange is that I 
was in one dir
and unfortunalty I don't remember which and it was crashing. I changed 
dir and then it was
working. In the first instance I didn't thought about taking notes but 
atleast I have a full trace
(the machine didn't hang or reboot... it is still alive 100%).

config is in attachment.

I don't know if it moght be relevant but I have also included the output 
from lspci -vv
The box is one of the "victim" of the ALI + Promise ATA100TX bug (thread 
of few days ago).

If you need more info please just contact me.

Regards
Fabio

Jul  7 18:03:57 trider-g7 kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000420
Jul  7 18:03:57 trider-g7 kernel:  printing eip:
Jul  7 18:03:57 trider-g7 kernel: c016351b
Jul  7 18:03:57 trider-g7 kernel: *pde = 00000000
Jul  7 18:03:57 trider-g7 kernel: Oops: 0000
Jul  7 18:03:57 trider-g7 kernel: CPU:    0
Jul  7 18:03:57 trider-g7 kernel: EIP:    0010:[devfs_generate_path+159/172]    Not tainted
Jul  7 18:03:57 trider-g7 kernel: EFLAGS: 00010246
Jul  7 18:03:57 trider-g7 kernel: eax: 00000000   ebx: 00000400   ecx: 00000000   edx: 00000040
Jul  7 18:03:57 trider-g7 kernel: esi: 00000002   edi: c6e0bf47   ebp: 0000003f   esp: c6e0be80
Jul  7 18:03:57 trider-g7 kernel: ds: 0018   es: 0018   ss: 0018
Jul  7 18:03:57 trider-g7 kernel: Process lvcreate (pid: 5939, stackpage=c6e0b000)
Jul  7 18:03:57 trider-g7 kernel: Stack: 00000006 c6e0bf08 00000000 c029bd9e c014b104 c26c4c40 c6e0bf08 00000040 
Jul  7 18:03:57 trider-g7 kernel:        c035c0d8 c02cc480 000001ad 00000000 c01abb92 c02cc480 00000006 c6e0bf08 
Jul  7 18:03:57 trider-g7 kernel:        00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 
Jul  7 18:03:57 trider-g7 kernel: Call Trace: [disk_name+84/540] [get_partition_list+186/344] [get_unmapped_area+213/268] [partitions_read_proc+26/52] [proc_file_read+204/420] 
Jul  7 18:03:57 trider-g7 kernel:    [sys_read+150/240] [system_call+51/64] 
Jul  7 18:03:57 trider-g7 kernel: 
Jul  7 18:03:57 trider-g7 kernel: Code: 83 7b 20 00 75 af 89 e8 5b 5e 5f 5d c3 53 8b 5c 24 08 85 db 

trider-g7:~# ksymoops
ksymoops 2.4.5 on i586 2.4.19-pre10.  Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.4.19-pre10/ (default)
     -m /boot/System.map-2.4.19-pre10 (default)

Reading Oops report from the terminal

Code: 83 7b 20 00 75 af 89 e8 5b 5e 5f 5d c3 53 8b 5c 24 08 85 db
Using defaults from ksymoops -t elf32-i386 -a i386


 >>edi; c6e0bf47 <_end+6aa52d7/84b1390>
 >>esp; c6e0be80 <_end+6aa5210/84b1390>

Code;  00000000 Before first symbol
00000000 <_EIP>:
Code;  00000000 Before first symbol
   0:   83 7b 20 00               cmpl   $0x0,0x20(%ebx)
Code;  00000004 Before first symbol
   4:   75 af                     jne    ffffffb5 <_EIP+0xffffffb5> 
ffffffb5 <END_OF_CODE+377e7236/????>
Code;  00000006 Before first symbol
   6:   89 e8                     mov    %ebp,%eax
Code;  00000008 Before first symbol
   8:   5b                        pop    %ebx
Code;  00000009 Before first symbol
   9:   5e                        pop    %esi
Code;  0000000a Before first symbol
   a:   5f                        pop    %edi
Code;  0000000b Before first symbol
   b:   5d                        pop    %ebp
Code;  0000000c Before first symbol
   c:   c3                        ret   
Code;  0000000d Before first symbol
   d:   53                        push   %ebx
Code;  0000000e Before first symbol
   e:   8b 5c 24 08               mov    0x8(%esp,1),%ebx
Code;  00000012 Before first symbol
  12:   85 db                     test   %ebx,%ebx