NextGen v99.1 not uploading pictures in WPMU

Hi I get this error when I upload a picture in NextGen:

ERROR: 061220081213.jpg :
Fatal error: Call to undefined function wpmu_enable_function() in /home/admin/public_html/modelsorg.com/wp-content/plugins/nextgen-gallery/admin/wp25/functions.php on line 709

706 to 717

// **************************************************************
function check_quota() {
// Only for WPMU
if ( (IS_WPMU) && wpmu_enable_function(‘wpmuQuotaCheck’))
if( $error = upload_is_user_over_quota( false ) ) {
nggallery::show_error( __( ‘Sorry, you have used your space allocation. Please delete some files to upload more files.’,’nggallery’ ) );
return true;
}
return false;
}

// **************************************************************