[Plugin: Contact Form 7] Version 2.4 is broken

I’ll add –

With the plugin active all calls to the home page give:

Fatal error: Call to undefined function is_multisite() in /home/lhacom/public_html/wp-content/plugins/contact-form-7/includes/functions.php on line 104

Plus I got an email warning that the site had exceed a resource usage from the hosting company.

WP 2.92
Contact form 2.4

installed previous version – it worked!

thanks