ContuttoPDF install issues

Hi,

i am trying to get the contuttoPDF plugin working. i have installed it and ran the compatibility check – says every thing necessary is installed and creates a pdf. at first when i activated the plugin, i got an error about selecting a template. in wp-admin/options.php i tried to change the ctpdf_theme to default – it was blank. Not able to do this in options.php – save does not work. changed in the database and now it shows up as default. Now i get this error, any ideas?

Fatal error: Uncaught exception ‘PDFlibException’ with message ‘Invalid UTF-8 string’ in /usr/www/users/ayeconf/ayeconference.com/wp-content/plugins/contuttopdf/dompdf/include/pdflib_adapter.cls.php:736 Stack trace: #0 /usr/www/users/ayeconf/ayeconference.com/wp-content/plugins/contuttopdf/dompdf/include/pdflib_adapter.cls.php(736): PDFlib->stringwidth(‘? AYE Conferenc…’, 2, 6) #1 /usr/www/users/ayeconf/ayeconference.com/wp-content/plugins/contuttopdf/dompdf/include/font_metrics.cls.php(108): PDFLib_Adapter->get_text_width(‘? AYE Conferenc…’, ‘/usr/www/users/…’, 6, 0) #2 /usr/www/users/ayeconf/ayeconference.com/wp-content/plugins/contuttopdf/dompdf/include/php_evaluator.cls.php(66) : eval()’d code(17): Font_Metrics::get_text_width(‘? AYE Conferenc…’, ‘/usr/www/users/…’, 6) #3 /usr/www/users/ayeconf/ayeconference.com/wp-content/plugins/contuttopdf/dompdf/include/php_evaluator.cls.php(66): eval() #4 /usr/www/users/ayeconf/ayeconference.com/wp-content/plugins/contuttopdf/dompdf/include/php_evaluator.cls.php(70): PH in /usr/www/users/ayeconf/ayeconference.com/wp-content/plugins/contuttopdf/dompdf/include/pdflib_adapter.cls.php on line 736