If you are using a shared PC make sure you log out at the end of your session. This protects your account privacy and especially important if you use a PC in a public library or an internet cafe.
TC, is your plate actually marked 'KPM'? I only ask because the blue mark is very similar to some of the marks from the Royal Factory, Berlin.
Hi TC <waves>, is this site any use: http://www.auktion-bergmann.de/Katalog.aspx?a_id=3&s_id=304