Figured it out. After adding the block Create Post to the Homepage, the code for Create Post block read:

array (
'module' => 'system',
'method' => 'get_create_post_form',
'params' =>
array (

0=>0,
),
'class' => 'TemplServices',
)

I removed the 0=>0, from the array and it does create the new post correctly now.