Hello,
Please ignore if you have already tried this:-
Go to Tr: CRMC_UI_PROFILE and find out the layout profile assigned to your business role.
tr: sm 34 , maintain CRMV_UI_MPLAYOUT
and copy the maintained layout profile in a Z layout profile.
Change the header height to 0 (it is in pixels).
Attach this Z layout profile to your business role in Tr: CRMC_UI_PROFILE.
Hope this helps.
Regards,
Parveen