But I’m writing this because I’ve always had problems with the left click in Flash programs on Ubuntu, it doesn’t matter if it’s Karmic or Lucid, it always fails. Anyway, the fix is very simple, here is what you have to do:

You need to edit the file /usr/lib/nspluginwrapper/i386/linux/npviewer, for example using gedit. So, you can put in the terminal:

gksudo gedit /usr/lib/nspluginwrapper/i386/linux/npviewer

And you need to add this:

export GDK_NATIVE_WINDOWS=1

before the last line. You can see how it looks the file edited in my computer, but you could have more or less lines in yours. Then you save and restart your session by logging out and logging in again. That’s all. I’ve found this here. They also give you another method that I haven’t tested, but if you want to try it at your own peril… Oh, I almost forget, if you want to upgrade your system, the post say that you should quit this line before doing it.