[horde] FreeBusy in kronolith with strange behavior

[Michael Cramer]

we have a strange probelm with the freebusy urls in kronolith. when  
there are for e.g. 5 people taking place in the meeting all with a  
configured freebusy url (also members on the same horde system) and  
then open the event somtimes 2 urls can be loaded, sometimes no url  
can be loaded and sometimes a previosly loaded url can't be loaded  
now. is there anything that can be done to fix that problem? maybe  
this is a webserver problem or something else. anybody has also seen  
that behavior?