Regarding MPEG-4 HE-AAC conformance testing

Hi All,
I am presently working on MPEG-4 HE-AAC.
I faced problem with _twi(Twiddle)series,while i am doing the 
conformance testing.
The vector is showing that its of AAC MAIN profile.But my decoder 
supports only AAC LC profile.

So,is it necessary to test my decoder with _twi vectors?
And also which series of vectors are sufficient to test Sbr part.

If any one knows about this please mail me.

Thanks in advance,
Venu