My guess would have been that upload_max_size and max_post_size were too small.  Try this:

1) Create a file called psotdump.php as below:
<? php
    foreach($_POST as $posted => $postedvalue)
        print($posted."=".$postedvalue."\n");
    foreach($_FILES as $upfile)
        foreach($upfile as $fileatt => $attvalue)
            print($fileatt."=".$attvalue."\n");
?>

2) Create an HTML file as below:
<HTML><body>
<form enctype="multipart/form-data" method="post" action="postdump.php">
<input MAXLENGTH="50" SIZE="40" type="file" name="file0"><p>
<input MAXLENGTH="50" SIZE="40" type="file" name="file1">
<p>
<input type="submit">
</p></form></body></html>

This site will explain any upload errors that may be displayed:
http://us3.php.net/manual/en/features.file-upload.errors.php

Hope it helps...
Brenton