Bios update on PE2850

[Lazy]

I'm trying to upgrade bios on our old 2850.
The system is Debian 4.0 64bit, omsa 5.3 is running correctly,
I tried this in single mode so there should be plenty of memory free
(3G installed)
Stock debian kernel 2.6.18-6-amd64.

./PE2850_BIOS_LX_A06.BIN
Collecting inventory...
.
Running validation...

BIOS

The version of this Update Package is newer than the currently
installed version.
Software application name: BIOS
Package version: A06
Installed version: A04

Continue? Y/N:Y
Executing update...
WARNING: DO NOT STOP THIS PROCESS OR INSTALL OTHER DELL PRODUCTS WHILE
UPDATE IS IN PROGRESS.
THESE ACTIONS MAY CAUSE YOUR SYSTEM TO BECOME UNSTABLE!
.
Enough contiguous physical memory is not available to perform the BIOS
update running under this Operating System. Reboot and try again.

BIOS
Enough contiguous physical memory is not available to perform the BIOS
update running under this Operating System. Reboot and try again.

Enough contiguous physical memory is not available to perform the BIOS
update running under this Operating System. Reboot and try again.


Any pointers what can be wrong?

-- 
Michal Grzedzicki