I think you are using a child theme of TwentyTen and in TwentyTen theme you have this line:
set_post_thumbnail_size( HEADER_IMAGE_WIDTH, HEADER_IMAGE_HEIGHT, true );
and HEADER_IMAGE_HEIGHT is 198px.
I think you are using a child theme of TwentyTen and in TwentyTen theme you have this line:
set_post_thumbnail_size( HEADER_IMAGE_WIDTH, HEADER_IMAGE_HEIGHT, true );
and HEADER_IMAGE_HEIGHT is 198px.