I run sugar 4.50h under FC5, httpd-2.2.2-1.2, mysql-5.0.27-1.fc5, php-5.1.6-1.2

Each tim I open an unread email I get hte following "Notice":

( ! ) Notice: Undefined index: action in /var/www/html/ipn_sugar/include/DetailView/DetailView.php on line 298
Call Stack
# Time Memory Function Location
1 0.0002 45176 {main}() /var/www/html/ipn_sugar/index.php:0
2 0.4924 2678128 include('/var/www/html/ipn_sugar/modules/Emails/DetailView.php') /var/www/html/ipn_sugar/index.php:663
3 0.9860 3066704 DetailView->processListNavigation() /var/www/html/ipn_sugar/modules/Emails/DetailView.php:256

when I re-open the email this notice does not show up anymore.

How can I fix this?

Thanks