Who have any solution!

I use Joomla 1.5.26 with JEvents 2.1.15 and module_mod_jevents_latest : 2.1.5.
When a public user look on my public calender it comes on the top of the calender the system message from Joomla. "You do not have access".
When I refresh again the site the system message does not shown.
Where I can switch off the system message for public user.
The menue type JEvents doesn´t show basics parameter to switch off the Joomla system message.

Many thanks in advance.
Arnie16