Display on main monitor is slightly too big

[MachoJamie]

I have a dual monitor set up with the same resolution and size. However, my main monitors display is ever so slightly too large on the left side cutting off some the picture. Any suggestions?

 

[ragnar-gd]

I can't say for a monitor for sure, but i had this problem on my LCD TV. My daughter(!) pointed me to HDMI-settings on the TV, switching the profile, and, presto, screen was centered.
It is something about the timings. Can't say more....