T510 w/FHD not showing fullscreen from hdmi

[Bray Matter]

so I got a t510 with FHD 1080p panel about a month ago and ran into a snag.

It would appear that when i connect a displayport>hdmi adapter to an hdmi cable to either of my hdtvs, it does not show fullscreen (black bars "all" around) and laptop pops up to use recommended resolution of 1680x1050. Tv reports signal at 1080p but it's like it's just not liking it.

What's even more odd, is that if I use a hdmi>dvi cable (my one tv has dvi), it does show fullsceen 1080p.

FYI - dp>hdmi adapter is from bytecc and I have updated all my drivers

any advice/ suggestions are appreciated

thx