Thanks.
I upgraded and succeeded to make this work, unfortunately this method does not bring the result I need using headers_as_string.
I will give you an example:
http://www.clipfish.de/player.php?videoid=MzkyOTN8OTA%3D
has a video inside.
There is no direct link to this video in the HTML source, the location will only be sent within the headers.
Using LWP::UserAgent with method progress does not bring this URL which is as follows (from LiveHTTPheaders-log, snippet from header):

http://pg1.clipfish.de/media/96/4efec90e3f12d631b4f5b490db152596.flv
GET /media/96/4efec90e3f12d631b4f5b490db152596.flv HTTP/1.1
Host: pg1.clipfish.de
...
[download]

Would it be possible to get the "host"-information and URL of the video from the headers using LWP or do I have to use another module or method?