You need to understand and work with the limitations of Flash. Xara can produce many "live" effects that are not supported by Flash. Most transparencies and transparency shapes are not supported. Stroke shapes are not supported, etc. This is not Xara's fault or Flash's fault. They are two very different applications that can communicate for the most part on a very basic level.

People who have learned to work within the constraints of both programs have produced some really excellent results. Egg and Squeaky are just two members of the community who have produced excellent work with Xara's SWF file format.