I've tried all the information in the Last.FM FAQs but without any success.
I'm scrobbling using MediaMonkey 3.1 and the latest official plug-in. The tracks show as 'Now Playing', but aren't added to 'recently played tracks' or the charts when they complete. Weirdly, the logs for the scrobbler report that the tracks are submitted OK:
8/5/2009 00:44:25.034: Last.FM: Submit Started at 1241739865
8/5/2009 00:44:25.061: Last.FM: Session ID fa52995551c14ca49f0629b367a40d74
8/5/2009 00:44:25.646: Last.FM: Submit Testament - Signs of Chaos
8/5/2009 00:44:25.917: Last.FM: Submit Started
8/5/2009 00:44:26.184: Last.FM: Submit OK
For some reason this is only happening on one of my machines. The only difference between the two is that one is a clean install of Windows 7 x64, and the other is an upgraded Windows 7 x86.