Coordinate transformation problem

[pcardinal]

I am using the coordinate system CANQ27-M8 in the source DWG and CANQ-M8 in the final DWG. No problem to query objects from the source DWG inside the final DWG

I am duplicating the NAD83 datum in the NAD83X (same parameters with a different name). I am referencing this datum (NAD83X) in a new coordinate system CANQ-M8X which is a copy of CANQ-M8 but with NAD83X instead of NAD83. Now it is impossible to query the objects from the source DWG (CANQ27-M8) in the final DWG (CANQ-M8X). Where is the problem because there is no difference between CANQ-M8 and CANQ-M8X save and except the name of the datum?