Today I was working on our AvantFax system so we could get a nice web interface to send faxes with. It turns out that I ran into issues even using the rh-install.sh script provided by avantFax.
CentOS 64bit 5.x system
Latest stable PHP/MYsql/Etc...
I found that I was getting the folowing error in /var/log/httpd/avantfax-error_log
PHP Warning: File upload error - unable to create a temporary file in Unknown on line 0, referer: sendfax.php
I tried setting the upload_tmp_dir variable in /etc/php.ini as suggested by most forms/mailinglists etc.. This did not seem to have any effect so I did the following.
chmod 777 upload
Change upload_tmp_dir variable in /etc/php.ini to "/tmp/upload/"
Send fax using the avantFax web interface.
This time, I did not get the error. My fax was properly sent and shows up in the "archive" section as it should.
This was the only thing that seemed to make this work correctly. I hope this helps!