Hi.. I've been playing a bit with make bcheck, and it spotted some binary 
incompatibilities.

The first one is in KIO::Job. There is a new virtual:
	virtual void removeSubjob( Job *job, bool mergeMetaData, 
			bool emitResultIfLast ); 
This breaks the vtable layout, and in particular changes the vtable offsets of 
public methods like:
	KIO::SimpleJob::putOnHold, 
	KIO::SimpleJob::slotError
and many others.

KNS::DownloadDialog is incompatible due to a size change: there is an extra 
field, QString m_providerlist;

Similarly, KNS::Engine adds in  bool mIgnoreInstallResult;

KIMProxy also changes layout:
+               // list of the strings in use by KIMIface
+               QStringList m_presence_strings;
+               // list of the icon names in use by KIMIface
+               QStringList m_presence_icons;
                // cache of the client strings in use by each application
                // dictionary of KIMIface_stub -> map of numeric presence -> 
string presence
-               QPtrDict<PresenceStringMap> m_client_presence_strings;
+               //QPtrDict<PresenceStringMap> m_client_presence_strings;

Note: I can not guarantee that this list is exhaustive

-Maks