New Weaver 1.5.1fatal error

hey there, I just updated to the new Weaver 2010 v.1.5.1 . it appears to have saved all my custom colors in Main Options, but isn’t using them, so when I try and change anything , and click Save Current Settings, I get this message:

Fatal error: Call to undefined function: fprintf() in /usr/local/pem/vhosts/230291/webspace/siteapps/98752/htdocs/wp-content/themes/2010-weaver/ttw-generatecss.php on line 42

please help, I have a Christmas Eve blog due out I’ve promised!!