Adobe did warn the Linux users: flashplugin version 12 has to be the last version for Linux. Version 13 (already available for Windows) will never come.
So we will have to accustom us with bad message requiring that we have to actualize (or we need a freak patching the version no. in 12 to 13, and in the future 14 etc. (::) !)
But it is not important if nothing changes in the actual media world: Very old flashplugins versions continue to work perfectly on webside making no version control, so youtube! I very often remaster my mini linux and for reason of memory, I install a version being a lot of years old (only 9.740 kByte! The actual version 12 is double more big!)
In my opinion there are not more essential functions in the new versions but only more barrier against copy because the customer of Adobe are not happy if the end user can copy her videos without embarrassment! The version control give better protection...
The point why libflashplayer.so does not work is rarely the lib itself but wrong links to it in the system!
The kind to place links for Mozilla is often clear as far you don't use the libre versions of it: They search the plugins in her own lib dir in the subdir (f. ex. /usr/lib/seamonkey/plugins ) or if not available there at the central place in the dir mozilla (in /usr/lib/mozilla/plugins). But, depending from the distro, a little supplementary software is often required to make it operable!
For midori, I did often search where are the rules for libflashplugin.so, java, as well as for gnash and Icedtea but did never find them :( . So it stay an occult science for me (it is possible that the sources scripts contains such indications?)
Same thing for the libre mozilla. Icecat, it is his name, is terrible difficult to install (I am using the version 10.0 of Icecat; but I did not really install it but only copy from the very unique distro http://dragora.com including some lib needed by Icecat. In dragora, the directories for icecat / gnash / icedtea and ~/.gnuzilla are completely new mixed in the file system! please look exactly in /usr/lib as well as in /usr/share if you don't want to miss some important part to use them (::) !). I did try to make the same with the Icecat from Arch but did not have some success...
I would be really highly be interesting to get ALL THE ACTUAL FREE STUFF from GNU ready to use as package in Slitaz (Libre Kernel, Icecat, Gnash and Icecat), as I find that if some idealist spend time and energy to preserve us a libre world, the least we can do would really be to use it, before we only build a monument for that people but continue to use the polluted one only of comfort!