Graphics n00b needs help, nVidia Geforce Go 7300

(Note, I've posted this on another website, but didn't get any useful replies. To see what others have said look here: http://www.techimo.com/forum/showthread.php?t=177446. See notes at bottom as well.)

Hey there. I am what you would probably call a graphics card n00b. I know that big numbers = good and integrated = bad, but that's about it.

Anyway, I recently bought this laptop that claims to have an nVidia Geforce Go 7300 in it. The reason I liked this was because the spec in the shop said that it has 256MB of dedicated graphics. "Awesome" I thought, and all the other specs were way above what I was looking for, and it was in the price range, so I got it. In fact, here it is:
http://www.comet.co.uk/cometbrowse/product.do?sku=362182&tab=specification#spec

Anyway, looking at dxdiag it says I've got 512MB of Video Memory "Integrated RAMDAC". Now, when I was searching for laptops (before I got this one) in PC World I came across this:
http://www.pcworld.co.uk/martprd/st...u=176555&page=Product&fm=null&sm=null&tm=null
Which I thought looked fine. I assumed that because it said it had an nVidia graphics card that it would be dedicated. I went to look at it in the shop, called up dxdiag and it says it has 256MB of Video Memory. So I asked the staff, and they thought it probably meant it was 128MB dedicated, 128MB shared. Then I spoke to someone else in PC World and it turns out that it does say somewhere on that page that it's got 128MB shared, so if anything it has got 256MB shared. Well I wasn't really interested from that point on.

Anyway, so what does this mean about my laptop? Is it running 256MB dedicated and 256MB shared? Even if that's true, looking up the Geforce Go 7300 on wikipedia (and others):
http://en.wikipedia.org/wiki/Comparison_of_NVIDIA_Graphics_Processing_Units#GeForce_Go_7_series
It says the maximum memory for the 7300 is 128MB.

Anyway as a graphics card n00b this is beyond me now. I kinda just want to know what I've got. If I don't have 256MB of dedicated then Comet are giving me my money back! (And I realised while doing this post that I could've got it for £100 cheaper if I'd got it online.)

Thanks very much,
Andrew

Notes:
On the other forum points were raised. Such as, I should be able to tell how much is integrated by looking at how much RAM I've got compared to how much I know it has. I know it has 2GB, the system says it's got 2046MB. I don't think it's got 2MB of integrated graphics somehow, lol. But it can't have 512MB of dedicated can it? Also, how can I possibly have 512MB if the highest for this card is 128MB? 384MB of integrated? Sounds strange. Any help would be appreciated, thanks.