Add a temporary workaround for a buggy QTimer::isActive()

The isActive() calls seems to return 'true' sometimes even though
the timer is not active anymore. This will result in missing timeout()
signals and therefor missing collection statistic updates.
The workaround doesn't check for timer activity but always stops and
restarts it. This is not the smartest solution but should work 100%

svn path=/trunk/KDE/kdepimlibs/; revision=1205152