I am using the high contrast inverse theme in 12.04 as I am visually impaired. This generally works great but causes a problem in Firefox as entered text e.g into a Google search is white. As the text background is also white you cannot see what you are typing.
I have read through a good thirty websites with similar issues but thus far nothing works.
I have tried all the settings in Firefox like un-checking "Use System Defaults" as well as manually telling Firefox what colours to use and these setting have absolutely no effect on anything.