I agree with airsupport. You definitely need to tilt down at cruise altitudes. Just always tilt so as to paint a little bit of ground and you'll be fine. Paint too much ground or too little ground and you won't see the cells very well. It only gets difficult when aiming at water, which won't paint, and mountains or major cities, which paint too much. In those cases just use the regular tilts that you would ordinarily use and just realize the ground paint won't look quite right temporarily.

Another thing to remember on the CRJ is that any gain other than normal disables the PAC alert. (Attenuation warning, for non-CRJ guys)