By manually creating a directory called “phpFlickrCache” in wp-content/blogs.dir/2/ this resolved the issue.
Might be way off base but; possibly this directory was restricted and did not allow the mkdir command on line 40 to work? Maybe add a check to see if directory exists on activation? e.g. if(!is_writable($upload_dir[‘basedir’].’/phpFlickrCache’) || !is_dir($upload_dir[‘basedir’].’/phpFlickrCache’))
