Error in Yahoo search results

Hello

After putting in the keywords “green business” at Yahoo I click on my site and an error message pops up:
Fatal error: Call to undefined function: iconv() in /home/content/c/a/n/canadianmale/html/traffic/Php/log_function.php on line 412
This does not happen with any other search engine, just Yahoo. Do you think that it is a problem with my site, or is it Yahoo’s error?
My site address http://www.futureofbusiness.info
site name: Green Business
I’m at a complete loss, and have called my host as well as searching for this problem all over the net.
Thanks
Rob