Access Violation using QRDesign with QuickReport in Dll


I made a dll with QRDesign and Quickreport, when I call it and show the
preview, it's ok.
But if I press + or -  in the zoom button,  when I close the preview I
receive this message:

Exception EAcess Violation in module Mainproject.exe at FFFFF009.
Access Violation at address 00000009. write of address 7004650E

Exception EAccess Violation in module Mainproject.exe at 00002E1C.
Access Violation at address 00402E1C in module Mainproject.exe.
Read of address 03921E4C.

A win32 API function failed.

Please, do anyone knows how I solve this ?