[Plugin: WordPress Stats] I get this strange warning

Hello, I’ve been running the WordPress Stats for a while now, and since one day the people I have my domain with updated something, I get this strange warning message with the stats in the main window.

Warning: tmpfile() [function.tmpfile]: open_basedir restriction in effect. File(/var/tmp) is not within the allowed path(s): (/usr/home/slynation.com/:/usr/home/phpMyAdmin-plan6/:/usr/home/webstats/) in /usr/home/slynation.com/web/wp-content/plugins/stats/stats.php on line 761

I don’t know what to do to make this go away. Since this warning appeared I can’t see the top posts and all that in the main window.

Can someone please help me. Thank you very much.