custom theme doesn't work

[e-tinchux]

Hi! I recompile Owncloud desktop client for WIN and I can not see my custom images (welcome.bmp and page_header.bmp).
I tried modifying client/admin/win/nsi/welcome.bmp and client/admin/win/nsi/page_header.bmp and also I tried using de replacement alternative..setting to 1 OWNTHEME=0 on the config file an running makewinlin.sh again, for this alternative I made a custom configuration in this file administration/build-clients/replacements/mytheme/OEM.cmake but still I can not see the images in the installer wizard.
My custom images are a little bit bigger than owncloud's images there are any hash indide the code?

Thanks in advance
Regards.