On the first loading of the java applet with Opera - the message - cannot find the file "msvcr71.dll" is issued.
Nevertheless it is in the directory C:\Program Files\Java\jre1.6.(v) \bin.
Extending the path specification under Start / Settings / Control Panel / Advanced system settings / Environment variables / System variables / Path with »C:\Program Files\Java\jre1.6.(v) \bin« solved this problem.