Damn, how I hate those wobdesigner idiots that make you click on virtual keyboards to enter your passwords. Virginmoney/Westpac has such a thing, and a very crappy one, too, but we have a fix. All this involves EczemaScript, not nice but better than suffering.
Now I've got another set of suckers to deal with, Citibank AU. Their setup is less gnarly but still annoying. This time, I produced a fix myself: Citibank-Demouse is a Greasemonkey script that simply clears the hooks that invoke the virtual keyboard; and hey presto! keyboard-entry of your password works again.
Federico Schwindt pointed out the appropriate Citibank UK url, and the script has been updated with this information.