QHostInfo doesn't finish internal threads when destroying

The following problem with QNetworkAccessManager has appeared after Qt 4.6.1 update. When QNetworkAccessManager is destroyed, internal threads are still running and when control leaves main() proc, an error message from Qt core is displayed.

Here is output from the attached test program:
C:\Documents and Settings\user\Visual Studio 2008\Projects\qt.test>release\Qt_4.6.1_NetworkBug.exe
QWaitCondition: Destroyed while threads are still waiting

C:\Documents and Settings\ user \Visual Studio 2008\Projects\qt.test>debug\Qt_4.6.1_NetworkBug.exe
QWaitCondition: Destroyed while threads are still waiting