Gradient export problem

Hey,

I'm new with CorelDraw (newbie). Actually just started using it 3 days ago and already facing a problem with exporting a file with gradient overlay. I'll attach screenshots how does it look in CD vs exported to pdf. To be more specific I'm making a package design. Could somebody help me with this? :) 

Gradient overlay in program. 

After exporting to PDF file.

Thank you for your help.