Samsung 226BW not respondig in D-mode during BIOS

Hi.
I'm new to this forum (and to the site as well...) & not so good with english, so forgive me for that...

I have 2 questions about LCD screens, and the technolegy behind them.

Starting with the specific one:
a. I've bought a Samsung 226BW (22" Wide LCD) a long time ago, and just lately i've notice I have a HD-out in my graphic-card (ATI RADEON 9000 PRO).
I pluged the screen to the CP on the spot, without turn it off (wrong,I know), and when I tried to switch to Digital mode - nothing happend. The screen was black. I tried to turn it and the comp off and on - not working. I managed some solution by updating the Graphic-card and the screen driver, and the screen actually working in Digital mode.
But not all perfect.
My problem now is that during the start-up of the CP, the whole BIOS proccess - the screen is blank, and its power-light blinks, as its not getting any power. Just when I reach to the Users Login (windows XP) screen - it suddenly turn on. Is this how it should be? I don't think so...

And a bit more general question:
b. In short -what's the difference between the Digital and the Analog mode, anyway? I know that in Digital mode, the screen get the data with no need to convert it, but what is that saying? because, to tell the truth - I havn't notice any difference between the two. I'd happy to reffered to a summerized article that explain the basic of that...

Many thanx!!