issue with directory/functions

I have no idea whats happening here.
Pages all still work ok, but can’t get this to disappear…
link of example where this is happening – https://engage.monkeysbrother.co.uk/portfolio-items/sport-4-nrg/

Warning: file_exists() [function.file-exists]: open_basedir restriction in effect. File(/.) is not within the allowed path(s): (/home/monkeysb:/usr/lib/php:/usr/php4/lib/php:/usr/local/lib/php:/usr/local/php4/lib/php:/tmp) in /home/monkeysb/public_html/engage/wp-content/themes/showycase/functions/vt_resize.php on line 67

help!