Flash data, Redirect and a Blank Screen

[eluser]Clooner[/eluser]
I never had to use flash data before but now I need to save some post data after a redirect. However when I set the flash data using $this->session->set_flashdata($key,$value) I get a blank screen on the page I get redirected to.

How is this possible or am I using the flash data wrong?

This is how I save the data and do a redirect to a different function in the controller

Code:

if ($this->input->post('price'))
    $this->session->set_flashdata('price', $this->input->post('price'));
if ($this->input->post('relation'))
    $this->session->set_flashdata('relation', $this->input->post('relation'));
if ($this->input->post('category'))
    $this->session->set_flashdata('category', $this->input->post('category'));
redirect('import/step2/'.$data['file_name']);

At this stage I do not even try to access the flash data on the page I get redirected to. When I remove the set_flasdata calls everything gets displayed just fine