Reversing broken updates

[James Taylor]

I would like to know how best to revert to an earlier version of 
PulseAudio. The reason is that an update to PulseAudio broke my ability 
to capture sound on my netbook.

I use aptitude for my package management needs and looking in its log I 
saw the following (hopefully) useful version information:

Will install 14 packages, and remove 0 packages.
===============================================================================
[UPGRADE] libpulse-browse0 1:0.9.14-0ubuntu20.2 -> 1:0.9.14-0ubuntu20.3
[UPGRADE] libpulse0 1:0.9.14-0ubuntu20.2 -> 1:0.9.14-0ubuntu20.3
[UPGRADE] libpulsecore9 1:0.9.14-0ubuntu20.2 -> 1:0.9.14-0ubuntu20.3
[UPGRADE] pulseaudio 1:0.9.14-0ubuntu20.2 -> 1:0.9.14-0ubuntu20.3
[UPGRADE] pulseaudio-esound-compat 1:0.9.14-0ubuntu20.2 -> 
1:0.9.14-0ubuntu20.3
[UPGRADE] pulseaudio-module-gconf 1:0.9.14-0ubuntu20.2 -> 
1:0.9.14-0ubuntu20.3
[UPGRADE] pulseaudio-module-hal 1:0.9.14-0ubuntu20.2 -> 1:0.9.14-0ubuntu20.3
[UPGRADE] pulseaudio-module-x11 1:0.9.14-0ubuntu20.2 -> 1:0.9.14-0ubuntu20.3
[UPGRADE] pulseaudio-utils 1:0.9.14-0ubuntu20.2 -> 1:0.9.14-0ubuntu20.3
[UPGRADE] totem 2.26.1-0ubuntu5 -> 2.26.1-0ubuntu5.1
[UPGRADE] totem-common 2.26.1-0ubuntu5 -> 2.26.1-0ubuntu5.1
[UPGRADE] totem-gstreamer 2.26.1-0ubuntu5 -> 2.26.1-0ubuntu5.1
[UPGRADE] totem-mozilla 2.26.1-0ubuntu5 -> 2.26.1-0ubuntu5.1
[UPGRADE] totem-plugins 2.26.1-0ubuntu5 -> 2.26.1-0ubuntu5.1
===============================================================================

I assume it is PulseAudio at fault rather than Totem. I am using an Asus 
EeePC 1005HA, with Ubuntu 9.04, and up until this problem hit me, the 
whole system had been working very well.

The question is, can I tell aptitude (or any other package manager) to 
go back and reinstall those specific earlier versions of the PulseAudio 
packages? If so, then please would some kind person explain how to do 
it. If this is not possible then:

I have a full backup of my system from before the audio capture was 
broken, but I have done a lot of work since and I would not wish to lose 
it all by restoring the backup in its entirety. Restoring just those 
files that relate to the pre-update PulseAudio would be better, but then 
I do not know how to be sure I am restoring the correct files and 
keeping the apt(itude) databases correctly synchronised.

Can anyone help me or point me in the right direction?

-- 
James Taylor