Urgent Help needed with Post method file upload

I'm attempting to post a file in a multipart/form-data post using LWP::UserAgent and the following command string:

 my $response = $ua->request(POST $baseurl, Content_Type => 'form-data', Content => [ request_params => $task_add_postkey, datafile => [$task_add_datakey] ]);


Where $task_add_postkey is a set of key value pairs of form data, and $task_add_datakey is the full path file name of a file containing binary data. The post seems to work fine with the exception of the 48 byte file I am sending, is received as 61 bytes on the server. I'm assuming it has something to do with how the file is being parsed. 

Is there a better way to put together a multipart post? Am I missing something obvious? Is there a way to control the file parser so that the data is handled as raw binary data? 

Any ideas????

Thanks in advance..

Eric