Hello, My name is ByungSoo Kim.

Problem.
 When I uploads some files over 8MB size,
 the values of POST variables changed to NULL.

 <FORM METHOD=POST ACTION="test.phtml ENCTYPE="multipart/form-data">
 <INPUT TYPE=text NAME=TO>
 <INPUT TYPE="FILE" NAME="USER_FILE1" SIZE="30">

 .test.phtml

  $TO value "" <- "test"  ...

Have a nice day.