Dell BIOS and SD Card Boot

I have Dell Inspiron N3010 (from 2010) with the latest BIOS A11...

I have tried so much to boot from SD card (it has sdcard reader). I have never FULLY succeded. I think this is important especially for protecting computer... ( i will come to this... )

With USB sdcard adapter you can boot your sdcard but not as fast as internal reader. (i assume your bios set up correctly with usb support and boot order)

The second way is strange. More likely a bug/glitch in software. Procedure is:

Apply standard usb boot things. Put Removable Add-in cards for first boot device, then usb then hdd etc...

Turn off computer (cold state - i mean no reboot) plug your usb device and sdcard. it is important to only one usb must be connected. not more!

sd card in reader should be mounted properly (with click voice)

Now this is you should be little fast. Power on machine, DELL logo will appear. When loading bar is stops moving. (approx. between 50-70 percent) plug out the usb key!

if you properly setup your sdcard (master boot record - mbr / partition is active) it will boot into live system...

The thing about progressbar is i think bios reading usb devices for boot. when you eject your usb. it drops to sdcard...

I have no idea to where to announce this. Research on google doesnt show me that... :)

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About protection of pc and sdcard;

My machine some kind steal-protection in bios but it is limited to USA/Canada. In my country i have developed a system which is usb or sdcard behaves as key (key to lock).
BIOS is password protected. harddisk boot is disabled. only usb boot is enabled in the order. (if there is sdcard boot i could enable it and disable usb boot - which is more complicated than usb drive - for example altering system passwords by formatting machine)
internal harddisk doesnt have any mbr and active partition.
usb is configured to chainload internal harddisk when booting. but this is not enough. it is loading by uuid of partition. so partition direcly booting from 'key'
also i have added a hash to boot parameters so there is verification... 
but it is avoidable with proper usb key. w/o sdcard boot it is not secure as:

only boot device is internal harddisk. and hdd has mbr record with small boot partition for redirecting. this part. have redirect for proper sdcard uuid AND s/n. this is hardcoded into bootlader. this means you cannot edit parameter and use another card. it is special for computer and its 'key'
after all SD card re-redirects into hdd partition 2 (which is part.1 in normal dell setup / recovery partition)
and partition 2 sending us to start windows. on partition 3.
partition 4 may be extended volume or user's primary volume for data or linux's /home folder.

anyway this is can avoidable through removing bios battery. if this is not possible in steal scenerio there is no way to aviod this method. only problem is sdcard boot...
another thing is first little boot sector searches for card but it has to be in bios memory or something to pass. first forward is low-level. bios doesnt see sdcard as storage device so doesnt pass this

SO, WILL IT FIXED? OR MAYBE YOU SHOULD DEPLOY A PATCH... I PLEASED TO USE A12 BIOS...