GD functions don't delete temporary files

I am using GD image function with PHP (PHP 4.3.9 on RedHat 9). Today I found that for all images I have created so far (using the ImageGIF() function), there is a temporary file in /tmp with that image. The name of the temp file is a 6 character combination of letters and digits, e.g. "jvc5Ne". To be sure it's not a config problem, I compiled again with minumum options and minimum script ./configure --with-gd --with-zlib <?php $im = ImageCreate(20, 20); ImageGIF($im); ImageDestroy($im); ?> But the problem is still there (CGI and CLI sapi tested). I used the "-n" option, so php.ini can't cause the problem, either. Has anyone else experienced that? Regards, Steve