I appreciate everyone's advice!
I double-checked his scores and everything I wrote in the previous post is correct.
I'm just working through the results right now and coming to the obvious conclusion that it's just a test and I still have the same kid. He will be taking the ITBS and CogAT testing in late spring at his private school. If those results come back very high then I will look into SCAT or Explore.
I remembered yesterday that my daughter-- now 13-- took a g/t qualifying test (I don't know what it was) when she was 8 years old. I thought it would be a no-brainer that she would get in. I was stunned when her test came back 55th percentile (97th was required to get into the program). She wasn't tested again until last year when she hit the ceiling on her CogAT. At 13 she is a sophomore, makes straight A+ on her report cards with barely any studying, and is on track to graduate from college with quite a bit of college credit under her belt at the age of 15. She is obviously above the 55th percentile in her abilities.
So... maybe my son will be the same way. Perhaps like his sister he just doesn't test well at this age. Or, maybe he has a totally average IQ, and I should be thankful for that. Who knows. I guess time will tell.