boot hangs while loading kernel

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

I have a machins where boot hangs when loading a large kernel. What is
odd is that the same bootloader and kernel loads fine from an USB stick,
while it hangs from a CF. 

Here is how tha CF (where it hangs) is attached:

mainbus0 (root)
mainbus0: Intel MP Specification (Version 1.4) (Intel    MoonCreek   )
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
piixide0 at pci0 dev 31 function 1
piixide0: Intel 82801HBM IDE Controller (ICH8M) (rev. 0x03)
piixide0: bus-master DMA support present
piixide0: primary channel configured to compatibility mode
piixide0: primary channel interrupting at ioapic0 pin 1
atabus0 at piixide0 channel 0
piixide0: secondary channel configured to compatibility mode
piixide0: secondary channel ignored (disabled)
wd0 at atabus0 drive 0: <CF CARD 4GB>
wd0: drive supports 1-sector PIO transfers, LBA addressing
wd0: 3831 MB, 7785 cyl, 16 head, 63 sec, 512 bytes/sect x 7847280 sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 4 (Ultra/66)
wd0(piixide0:0:0): using PIO mode 4

And here is the USB stick:

ehci0 at pci0 dev 29 function 7: vendor 0x8086 product 0x2836 (rev. 0x03)
ehci0: interrupting at ioapic0 pin 23
ehci0: BIOS has given up ownership
ehci0: EHCI version 1.0
ehci0: companion controllers, 2 ports each: uhci0 uhci1 uhci2
usb3 at ehci0: USB revision 2.0
uhub3 at usb3: vendor 0x8086 EHCI root hub, class 9/0, rev 2.00/1.00, addr 1
uhub3: 6 ports with 6 removable, self powered
umass0 at uhub3 port 2 configuration 1 interface 0
umass0: Imation Pivot, rev 2.00/1.00, addr 2
umass0: using SCSI over Bulk-Only
scsibus0 at umass0: 2 targets, 1 lun per target
sd0 at scsibus0 target 0 lun 0: <Imation, Pivot, 1.20> disk removable
sd0: 3855 MB, 500 cyl, 8 head, 32 sec, 512 bytes/sect x 7895040 sectors

Any idea of what I can do beside always booting off the USB stick?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost