Cannot Get ACER 27" Monitor to Utilize Full Screen!

Hello! I just purchased and setup my new ACER 27" (S271HL) monitor from newegg.com. I set the screen resolution to 1920x1080 but there are still black bars on the sides and the top and bottom. It is just not utilizing the full 27". When I set it back to 1680x1050 (my old 22" monitors resolution) the screen then fills up. When I go in game though (@ 1920x1080) it still has the black bars all around. I've even gone into the Catalyst Control Center (I have a Radeon HD 5870 GPU) and tried messing with things. The max resolution is 1680x1050. It states it is in 1080p 60hz Mode. I'm looking for any suggestions so my screen will look full! I feel like I am missing something simple. Please post your suggestions and let me know what other information you may need from me to get this solved. I look forward to any and all of your comments!

Thanks for your time!

- manooly