D&D 4E Sleep / Burst Question in 4E KotSF

[Dax Doomslayer]

Hi Folks,
In the sleep description on the Wizard's pregen for Keep of the Shadowfell it states "Area Burst 2 within 20 squares". I understand what the "Burst 2" conveys but what is the "within 20 squares" connote? In addition, there isn't a 'range' listed. Is this intentional? Any help here is greatly appreciated. Thanks.

 

[Mort_Q]

The within 20 squares is the range. The center of the burst must be a square within 20 squares of the caster.

 

[blargney the second]

The range is 20 squares.

 

[baberg]

Pick a square within 20 squares of you. That's the center of the Burst 2 (5x5 square).

EDIT: Changed 3x3 to 5x5.