kernel panic - not syncing: VFS - unable to mount root fs on unknown-block

[Hulin Thibaud <hulin.thibaud@wanadoo.fr>]

Hello !
I'm trying to compile my own kernel for drivers on two computers, but 
that fails. A the boot, I have this error :
kernel panic - not syncing: VFS Unable to mount root fs on unknow-block 
(3.69)

I'm using the kernel 2.6.19 with Ubuntu Dapper. I use the old boot 
config and I type make oldconfig, so I don't understand why there are an 
error with the near same configuration.
I suppose that I must compile not in module but in hard support for my 
IDE chipset, harddisk and file system. Probably, I don't understand how 
do exactly. I do that :
lspci |grep IDE
0000:00:11.1 IDE interface: VIA Technologies, Inc. 
VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
make xconfig
-Device Drivers
--* ATA/ATAPI/MFM/RLL support
--- * Enhanced IDE/MFM/RLL disk/cdrom/tape/floppy support
--- * Include IDE/ATA-2 DISK support
--- * PCI IDE chipset support
---- * Generic PCI IDE Support
----- * VIA82CXXX chipset support
- File systems
-- * Ext3 journalling file system support
--- * Ext3 extended attributes
---- * Ext3 POSIX Access Control Lists
---- * Ext3 Security Labels

Have I forgot anything ?

Thanks very much,
Thibaud.