That is likely lost due to overscan then- in Television the picture usually goes past the visible screen so you never see the edges- the area about 10% in from the edge is considered the "safe" area- you'll never see anything of vital importance (phone numbers, sub titles, etc...) put too close to the edge because they can't be sure every TV will show up to the edge.
Now most TV's I've seen are usually built "smart" enough to know when using a computer input there doesn't need to be overscan at all... I say "most" because my own HDTV is like yours and was not built this way- at full resolution I lose about 10% of my screen on all sides due to overscan.
With PowerStrip however I was able to choose a resolution just a little smaller than the native resolution and it fit my TV screen perfectly.
But it's been 3 years since I did this so I'm trying to remember my exact steps. Does PowerStrip give you a number of resolution options? I had maybe 3 or 4 options before PowerStrip, after installing I had like 10 choices... one of them worked perfect.