Yeah, unfortunately this happens a lot with programs like this. They are usually excellent and accurate, however there is no way that the programmers can test every piece of hardware. You might want to send them an email with your CPU, Motherboard/Chipset, and Ram (and describing the problem, or pointing them here) so they can try to fix it in future releases.
This is marketed as a 1gb module but click the picture to enlarge and go to the second picture. On the right side it specifies 1024mb. 1gb is easier to say than 1024mb and close enough to it, so the computer industry often times refers to 1024mb as 1gb.
The first two links you provided don't work for me, but if you installed 4gb and it reads 4096mb, then you're good.
note: A good general rule in computing is that things happen in powers of two. 2^10=1024, 2^12 = 4096.