I don't know exactly what you are doing, but here's a trick I came up with:
There are objects, with certain properties, which CorelDRAW does not convert to Symbols. CorelDRAW Help calls them "Unsupported Objects".
The trick is to PowerClip the unsupported objects inside a supported one, then convert the PowerClip group to a symbol.
Try it and give us your feedback. I didn't test it on printing.
Note
In CorelDRAW 11, sometimes I get the C.A.R.M. wizard when I have a symbol with unsupported object.