Taj Gibson didn't worry when Chicago fell behind Dallas early, and he wasn't concerned when the Mavericks made a late run for the lead. The Bulls had answers both times. Gibson scored 20 points and grabbed 15 rebounds, Mike Dunleavy hit a go-ahead 3-pointer and Chicago overtook the Mavericks in the fourth quarter of a 100-91 victory Friday night. ''We're used to this,'' Gibson said after the Bulls (32-26) won for the eighth time in nine games, moved a season-high six over .500 and answered a 22-point home loss to Dallas in December. More...