If your CIR has been expired for more than 12 months (ie. 2 years since your initial issue or last renewal), You do not have to re-do your entire initial issue training. However, the renewal test required to be able to exercise the privileges of your CIR is the equivelent of an initial issue test and has to be completed entirely in an a/c.
Thanks Mike, I heard that from another CP as well. I find myself in that unfortunate position now.