Feeds Import Stuck At A Point (At any % sometimes - 29, 60.. etc)

hi ,
i am using the the code

feeds_batch('import', 'my_importer_id', $node->nid, $context);

given on - https://drupal.org/node/622700 (feeds developer guide)

i am using this code to execute the feeds import process Programmatically using a hook_menu.

I normal import using the webpage - website_address.com/import/content_type . works fine and shows me a blue progress bar .
but the same import when i trigger with hook_menu , and visit the page , website_address.com/import/content_type , shows me importing being stuck at a point (any percent value), and also there is no progress bar in this case .

then i have to unlock it and thats the only way it proceeds further.

please help me on this.