What is wrong with him?

Ok, so Shaney Poo Norris has had a rough couple of days. He's actually been a mad man...I'm not real sure what's going on with him. On Monday, he stayed with Annie and DD. He was fine when he woke up, brushed his teeth and went on over. Later in the day, they were headed to Gloucester and Shane became so out of control that they have turned around and brought him back home...it got worse as the day went on. When I asked him why he behaved that way, he told me that he didn't like the new flag that Annie had put outside....really, son?? Really?? After we picked him up, he apologized the rest of the night and was good as gold. On Tuesday, we had a talk that morning about his behavior, all was well. He went to school, all was well...Annie & DD picked him up and headed over to Gloucester--went to Lockwood's and looked at carpet, then lunch at Chick Fil A....that's where it went downhill. Shane wanted to climb up the slide in the wrong direction and when Annie told him no, the meltdown began...He screamed for the next 3 hours...When I walked in to pick him up, he started apologizing...I'm so sorry to Annie for having to deal with a monster for two days. I don't understand what causes these crazy meltdowns---i cannot describe to you what they are like---he's just out of control, it's almost like he's outside of his own body for the moments that his anger overcomes him...We have a new responsibility chart at home that outlines his chores that he has to do each day. For each thing he completes, he gets a "smiley"...Each smiley is worth 1 point. In order for him to be able to go on our planned November Disney trip, he has to achieve 600 points. Last night, he got NO smileys at all, not even for the things he had done. They were definately not deserved. Anyone out there got any suggestions for me? I know he's 4...but I also know he's very aware of what he's doing and that is is wrong. Bless his heart...