[horde] Problem with preferences backend

[Erik Quaeghebeur]

Hi,


I'm using Horde Groupware Webmail Edition 5.1.3 with Horde 5.1.5 (and 
other installed applications updated last week).

I very often get the following two notification messages:

	Error when communicating with the server.

	The preferences backend is currently unavailable and your preferences 
have not been loaded. You may continue to use the system with default 
preferences.

It is not clear to me whether they are related, although they do usually 
occur almost simultaneously. When I look at the Apache/MySQL/PHP logs, 
nothing suspicious seems to be going on and I do have a horde_prefs 
table. test.php shows all (required) dependencies are present. Looking 
at the Horde log files also does not give me any clue. On the other 
hand, I have little experience in these matters, so it is entirely 
likely that I am missing something.

I would be grateful if a person knowledgeable about Horde installations 
could help me diagnose this problem.


Thanks,

Erik