processFormSubmission error - Stream does not represent a PDF document.

Hi, I am facing problem with processFormSubmission component.

We´re using updated render process, but after server reinstall, I am using Default Render ES Update1and this component is returning me Stream does not represent a PDF document  error.

Environment settings I use:

&HTTP_ACCEPT_LANGUAGE=cs&HTTP_USER_AGENT=Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30)&CONTENT_TYPE=application/pdf&CONTENT_LENGTH=451429 .

I tried also different content_type var, it was not returning that err, but component was not able to save attachement list(what is important for me).

thanx for suggestion, thx... Lukas