CF 512M vs. CF 2G

Few days ago I got my hands on kingston 2GB CF card. I copied data from my 
previous Kingmax 512MB one to it and.. was surprised that I was not able 
to boot linux out of 2GB one. First I thought this is due to that linux 
ext2 partition begins too far from the beginning so I did 1:1 EXACT copy 
with dd from 512M to 2G. But still no go - from 512M card I can boot from 
2G card I can not - booting ends with kernel panic - unable to mount 
root="hda2".

Finaly I tried to use different kernel than 2.6.18 and here is summary:
Using 2.6.18-7xx or my older 2.6.13 kernel it is unable to mount rootfs. 
Using my older 2.6.12.5 and any of 2.4.x kernels it boots pretty fine.

Comparing the 2.6.18 logs from 512M and 2G boot, when booting from 512M 
the boot continues with:
user.info kernel: TCP bic registered
user.warn kernel: pcmcia: request for exclusive IRQ could not be 
fulfilled.
user.warn kernel: pcmcia: the driver needs updating to supported shared 
IRQ lines.
user.warn kernel: jornada720_pcmcia_configure_socket(): config socket 1 
vcc 33 vpp 0
user.warn kernel: jornada720_pcmcia_configure_socket(): config socket 1 
vcc 33 vpp 0
user.debug kernel: Probing IDE interface ide0...
user.warn kernel: hda: KCF512M-T^HKT2, CFA DISK drive
user.warn kernel: ide0 at 0xc2840000-0xc2840007,0xc284000e on irq 115
user.info kernel: hda: max request size: 128KiB
user.info kernel: hda: 1006992 sectors (515 MB) w/0KiB Cache, 
CHS=999/16/63
user.info kernel:  hda: hda1 hda2
user.info kernel: ide-cs: hda: Vpp = 0.0
user.info kernel: sa1100-rtc sa1100-rtc: setting the system clock to 
1970-01-01 00:01:14 (74)
user.warn kernel: VFS: Mounted root (ext2 filesystem).

while when booting from 2G one it panics right after
user.info kernel: TCP bic registered


Does anybody has idea what can cause this? Why newer kernels do not 
start "Probing IDE"?


Adam Pribyl