File Upload failing on Binary Files

I can't upload images though text is ok. This worked on earlier version of PHP and I don't know whether it is php, apache, or linux at fault. The post basic code is as per documented example. test_load.htm <FORM action="test_received.htm" enctype="multipart/form-data" method="POST"> <INPUT TYPE="file" name="userfile"> <INPUT TYPE="hidden" name="MAX_FILE_SIZE" value="200000"> <INPUT TYPE="SUBMIT" value="Send File"> </FORM> test_received.htm <HR> <? echo is_file_uploaded($userfile); ?> <HR> Results 90k text - 30 seconds - ok 2k gif - 20 seconds - ok but very slow 6k gif - Never completes. No binary file greater than about 4k completes. PHP 4.0..4pl1 Apache 1.3.12 Linux Redhat 7