I just wanted to note, that the root of all those crashes is not an ABI-
breakage or a bug in kdelibs. It's once more a problem with threading and Qt 
Sockets. The reason why >soprano-2.7.6 works is that it introduced 
Soprano::Socket.
I already wrote it in another bug report, that I extracted a patch from the 
diff between 2.7.6 and 2.7.56, that simply introduces Soprano::Socket to the 
2.7.6 Codebase - and all those crashes are gone, now running >2 days without a 
crash, without problems.

Is it possible, to release soprano-2.7.6.1 or so, that ships with 
Soprano::Socket? This would make it possible for distributions to ship a 
working kde-4.8.4 with only stable software.