I've been struggling, with the same LCD you are using, to get images to display correctly. Could you post a picture of what the bmp.h image should look like? Do you know if the controller on the Nokia display still supports 8 bits/pixel? I know you are using the 12 bpp mode but thought I would ask anyhow.
I'm starting to think the latest release of these displays has a controller that dropped the support of 8 bpp.
Thanks in advance,