As far as I know, does last.fm only accept scrobbled tracks, if there is a flag submitted at the end.
Seems, that current GIT doesn't send this flag.
Tracks appear at user's last.fm site as long as they are played as 'listening now'. On track change the track disappears and is substituted by the next in queue. Track count doesn't increase, too.
According to the changelog there were some changes in last.fm/kwallet issues.
Perhaps these cause the failed subscriptions. GIT from 29.05 worked btw.
This is GIT, so I won't fill a bug report.

Edit: trying to open last.fm setting causes amarok to not response anymore.

openSUSE 11.2¼
KDE 4.4.3
QT 4.6.2
liblastfm 0.3.0

m0nk