From looking at the forums for that software, it appears that the script relies upon allow_url-fopen being enabled, and it relies on that instead of using cURL.
Allow_url_fopen is disabled on DreamHost for security reasons (as it should be).
Your choices are to:
Recode the script to use cURL
Install your own PHP, or use a copy of DH PHP with your own php.ini to enable allow_url_fopen (please do not do this - it was disabled by DreamHost for a reason )
Use different software to accomplish what you are trying to do.
I vote for choice 3 - I use feed2js, and it’s related tools (magpierss), all the time on DreamHost, and it works very well.