User blog comment:Lemursrule/Bleach 422: New Arc Time!/@comment-1961713-20101001034141/@comment-1351982-20101001034548

I think since he is essentially a human soul now he is weakened by the intense spiritual pressure around him. Plus Kon is still in his body so since Ichigo's body was converted into spirt particles Ichigo does not really have a body to return to so maybe we are getting a case of rejection here.