Thanks for the php info page. i compared it to my settings and i could not see anything that is related to the server that could cause any issue. It seems that the issue is related to the path to the font.
If you could please open the:
WAVT_CaptchaSecurityImages.php page under the WA_ValidationToolkit folder and add these lines of code:
if(file_exists($font)) {
$font= realpath($font);
}
under line 123.
Please post back if you are still having the issue.