Description of problem:
Just prior to CGI 3.15, a bug was introduced into the upload() method (which
captures file handles for uploading files to Apache) so that it loses the
filehandle intermittently, causing uploads to work only every-so-often.  Since
v3.15, there have been multiple patches to CGI fixing the upload().

Version-Release number of selected component (if applicable):
The problem is in CGI 3.15.

How reproducible:
I don't know if it will help you to give you step here.  However, a link to the
CGI change log documents the problems with this:

http://search.cpan.org/src/LDS/CGI.pm-3.33/Changes

Additional info:
CGI 3.33 fixes this problem.  Since CGI is packaged into the perl package, it is
easier if the update comes through an update.