Annoying Problem

Hey guys, I recently got a Behringer Xenyx 1222FX and it sounds great. The UB2000 I think is a cool little toy (And a little off topic but all you have to do to get it to work is put the output on the board to the input on the UB2000, and vice versa. I saw many people were having trouble with this)

Anyway the thing is I can record and it sounds perfect. But when I go back on Audacity (Im sure you are all familiar with this program) and record a new track OVER the existing first track, it Re Records the first track and is off by a milli second. Now I can stop this by turning all tracks off except for the one I am currently playing but is a hassle because I cant play to a click track if i do this or hear what was previously recorded. I know these are NOT the causes:

The Speakers being turned on...I am using headphones.
The headphones too loud and the mic is picking it up.....I unplugged the headphones and it still does this.

Even if the mic is at zero volume it will do this.
Any suggestions? Its a pain in the arse.

Ive attached a soundclip with three tracks recorded onto it:
The first one is me talking.
The second track I hit record and do not speak, yet, you can hear a delay from the first voice.
The third track I hit record, silence all the tracks and do not speak. As you can hear, nothing from the first voice is recorded.
Any and all help will be much appreciated!