I have an old Shuttle computer in my garage that runs Ubuntu 10.04 and all of a sudden Flash has stopped working.
I decided, after many failed attempts to sort the problem, to reinstall 10.04.
A full installation later, updated to 10.04.4, Ubuntu Restricted Extras loaded and Medibuntu repository enabled and still no Flash
I have other computers running 10.04.4 and Flash works well.
Attached is the output of lshw should it help.