I checked my personal settings and the time offset was 0. I clicked the "auto detect" button and it changed the setting to 1. When I saved it, the displayed forum times (in posts and under the simple machines forum text in the upper right) now look correct.
However, the actual forum time as displayed under personal settings is still off an hour: Current forum time: March 16, 2013, 11:14:23 AM
I copied that at 12:14:23 PM.
No biggie just hoping this helps you resolve it. My guess is somewhere on the admin/server side there is a setting for daylight savings and it needs to be checked or unchecked.