No $_POST data

[eluser]Unknown[/eluser]
I had some problems with posting files, I didn't get any post variables.
I was using Codeigiters form:

form_open_multipart('admin/upload/...);


I fixed this problem with:

<form action="admin/upload/..." method="post" >


The codeigniters form displayed:
<form action="http://foo/admin/upload/..." method="post" accept-charset="utf-8" enctype="multipart/form-data">

and the problem it seems to be with enctype="multipart/form-data"