You'd get a better response in the SEM, ITB/ Carb forum. BUT Yes. You will have idle problems with ITBs. Its just the way it is. ITBs are SSSSSUUUUPPPPPERRRR hard to get to idle well.
Which tuning method are you using? Alpha-N or MAP? At any rate, try running it a little rich at idle. Warm it up and see if it gets better when not cold.