[imp] Error when saving eMail

[Klaus Weidenbach]

Hello,

I have updated from H4 to H5 and have hord 5.0.2 and imp 6.0.1 from PEAR. I 
just realized that when I want to download an eMail "Other Options --> Save" 
I get an error message. 

A fatal error has occurred
User is not authenticated.

1. Horde_Registry->callAppMethod() 
/srv/webs/webmail/horde/services/download/index.php:33
2. call_user_func_array() /usr/lib/php/Horde/Registry.php:1139
3. IMP_Application->download()

When I go back in the browser I am still logged in. Can someone reproduce it 
or is my configuration wrong?

Thank you very much!

Regards,
Klaus