PHP Notice: in file viewonline.php on line 229: Undefined offset: 1

I got this error message earlier when Yahoo Bot crawled my site.

The one thing I noticed was that in every report the url from the page it accessed had show guests set to true. I didn't get any without sg=1 in the url.

I couldn't get the error browsing myself, but it accessed my site about 1 1/2 hours before I noticed.