I have similar problem with an about 4.5 year old ACER Aspire E300 PC that is supposed to be able to take up to 2gb of ram. The system showed that I had 1 GB, so a bought an additional DDR-400 RAM bar, but the system is still showing only 1 GB RAM. I inverted the bar, but it did not help.
The Everest software is, however, seeing two bars. In slot 1 the new one (Kingston 1024 MB) and in slot 2 the old one, which it calls Nanya NT512D64S8HCOG-ST with 512 MB. If these data are correct the system should show 1.5 GB, but it still shows only 1 GB.
Has anyone else has this problem or does anyone have any ideas on how to sort it out? I have not yet contacted ACER.
Cheers also from me for any help guys