Comment 7 for bug 234188

What package is your flash plugin coming from? It is only relatively recent versions of flash that do fullscreen, and there always seem to be a lot of options covered

I get flash from 'flashplugin-nonfree', which provides 9.0.124, which can do fullscreen. From flash's release notes (http://www.adobe.com/support/documentation/en/flashplayer/9/releasenotes.html), fullscreen in Linux is from version 9.0.115 upwards.