I am using civicrm-1.8.beta.10790-drupal-php5.tar.gz and I have configured CiviCRM to use PayPal Standard in test mode. All transactions were done using test mode.
I created a custom field for contributions. It works fine. It appears in Find Contributions > Search > View.
I created a second group of fields for an event. The fields appear in the event registration, and appear in the event Thank You screen. But when I try to view these fields using Find Contributions > Search > View, the fields appear blank. They are also blank in the Thank You email.
The attachment is a zip file of prints of the screens and emails.