This supercedes my HOWTO posted some months ago concerning Opera's problem with the mplayer plugin on previous versions. However Opera has now thankfully solved the problem with Opera 9.50Beta. Unfortunately VL5.9 comes with Opera 9.23. Here is the upgrade method:
1) go to this site: http://www.opera.com/download/linux/?ver=9.50b
and download the Slackware 11.0, 12.0 version of Opera.
2) this is a tar.gz file you need to unpack (easiest to use "mc" in a terminal and then press F2). Or type "tar xzvf filename".
3) navigate to the new opera directory to where the tar file was unpacked.
4) su to root and type "./install.sh" and follow the prompts.
Opera's mplayer plugin does not work with RealMedia files so you will have to get the RealMedia player for those filetypes ( http://www.real.com/linux/
). For most other stuff it works. Note the BBC website still deigns Linux to be beneath them, but they are apparently now working on Linux versions of their streaming multimedia website, after much protest.