I too am getting a blank page after following the instructions to a T. Port 1129 has been opened, all of the files in their proper place, the PEM file uploaded, in live mode, debug off, etc.
The following is from the server error log... any suggestions???
Thanks for looking.
[Tue Oct 05 11:54:29 2010] [error] [client xx.xx.xx.xx] PHP Warning: linkpoint_api::require() [<a href='function.linkpoint-api-require'>function.linkpoint-api-require</a>]: open_basedir restriction in effect.
File(/www/xxx/httpdocs/catalog/includes/modules/payment/linkpoint_api/lphp.php) is not within the allowed path(s): (/var/www/vhosts/xxx.com/httpdocs:/tmp) in /var/www/vhosts/xxx.com/httpdocs/catalog/includes/modules/payment/linkpoint_api.php on line 358, referer: https://www.xxx.com/catalog/checkout_confirmation.php
[Tue Oct 05 11:54:29 2010] [error] [client xx.xx.xx.xx] PHP Warning: linkpoint_api::require(/www/xxx/httpdocs/catalog/includes/modules/payment/linkpoint_api/lphp.php) [<a href='function.linkpoint-api-require'>function.linkpoint-api-require</a>]: failed to open stream: Operation not permitted in /var/www/vhosts/xxx.com/httpdocs/catalog/includes/modules/payment/linkpoint_api.php on line 358, referer: https://www.xxx.com/catalog/checkout_confirmation.php
[Tue Oct 05 11:54:29 2010] [error] [client xx.xx.xx.xx] PHP Fatal error: linkpoint_api::require() [<a href='function.require'>function.require</a>]: Failed opening required '/www/xxx/httpdocs/catalog/includes/modules/payment/linkpoint_api/lphp.php' (include_path='.:') in /var/www/vhosts/xxx.com/httpdocs/catalog/includes/modules/payment/linkpoint_api.php on line 358, referer: https://www.xxx.com/catalog/checkout_confirmation.php