I have a very strange problem with flash on my 10.04 system. (An update to 12.04 is not an option, because the system is just too old and slow.)
After a recent update flash has just stopped working altogether. Youtube just shows a white square, vimeo a black one. After a 10.04 reinstall the problem stays the same. Not even chrome displays flash content, just a message that shockwave flash could not be loaded.
'ubuntu-restricted-extras' 'flashplugin-nonfree' and 'flashplugin-installer' are all installed in version 188.8.131.52ubuntu0.10.04.1.