How about firefox 3.6 in Fedora 12 ?

[M A Young]

On Mon, 1 Feb 2010, drago01 wrote:

> On Mon, Feb 1, 2010 at 9:30 AM, M A Young <m.a.young at durham.ac.uk> wrote:
>>
>> That doesn't work as nicely as perhaps it should because
>> yum downgrade firefox
>> only downgrades firefox and not xulrunner, and as a result the downgraded
>> firefox refuses to run. You need at least
>> yum downgrade firefox xulrunner
>
> yum history list
> yum history undo <number>

That requires you to remember when you did the update, or do more digging 
to identify the relevant update batch. I presume it will work, but it 
isn't quite as simple as you imply.

 	Michael Young