Java did an update the other day and twice since then (on opening Firefox first thing in the morning), I've been asked if I want to install an 'Ask' toolbar. There is no 'No' option. There isn't even a 'Cancel' option. There is only a box to click in so the toolbar will install.
Unless there is another way to stop this, the only way I can see is to install the toolbar and then uninstall it again.
Shame on Java for doing this. No other program should be mandatory during an installation.