First, might get better info and advice here if you included the model and link to specs on the netbook. Also should know the actual speed of current RAM.
Clearly the BIOS has the ability to adjust the ratio/multiplier between your RAM and FSB - it shows now that you're using 267MHz RAM and ratio is 1:2. I think this may actually be 533 RAM that the BIOS treats as 267 for its own reason? One thing to do is to explore the BIOS and see what settings can be changed. If you've got choices for RAM muliplier it may give you the answers. Be good to know if your current RAM is really 533 and see if you can set that ratio up to 1:1 based upon actual speed of RAM. A different stick of 533 might turn into 1:1 ratio and perform better.
Usually the RAM suggested in a manual represents the slowest/fastest RAM available at the time of the printing. Heck, the thing might support 1066 RAM and do a 2:1 ratio! Putting faster RAM often results in it being treated as slower - and it's always downward compatible - so the 800 will work fine as 533. And the prices for that product seem to be pegged at $30 regardless of 533 or 800. From what I read on the forums here, most would say go for the CL of 4 and 533 rather than the 800 and CL of 5.
Looking at this chart of Netbooks, only those using the Via processor go beyond 2MBs. I'm guessing that Intel limits the Adam to addressing only 2GBs. But make sure yours allows the 2! Someone spent some time getting all this info into Wiki, lots of info there.
Here's something I was working out when making decision about going with my 1066 RAM with higher CL over 800 with lower CL. I don't know if the numbers are really proportional like this, but it's something to consider.
If numbers and percentage increase really represent increase in speed then this works:
% change of speed going from 533MHZ to 800MHz:
267 = 33% increase
% change of speed going from CL=4 to CL=5
-1 = 25% decrease
So, based upon that, there's a net increase of speed for you in getting the 800 memory to work. That of course assumes that your 800 RAM would actually run at 800.
LOL, I looked over the manual for that model - it shows that you have an "Advanced" section in the BIOS, but doesn't even show the basic screen for it, much less if you can configure memory.
I'd look at the BIOS, see if it has anything about memory. And might be worth a shot calling Samsung support, they're good on monitor things, might be able to tell you if 800 is really supported as 800 rather than 533.