[horde] ingo: can't add rules

[A. Schulze]

Hello,

I cannot add/change ingo-rules anymore.
It definitly worked in 5.1.x but not in 5.2.x

After adding a new rule I get two green boxes "change saved" and  
"rules activated"
But after that the new rule isn't shown at all.

Also I found that in the log:
2014-08-04T20:26:12+02:00 WARN: HORDE [ingo] PHP ERROR:  
stream_filter_remove(): Unable to flush filter, not removing [pid 1378  
on line 65 of "/usr/share/php/Horde/Imap/Client/Data/Format/String.php"]

Do you need any further information?
Andreas