This is my third posting on my upgrade experiences with Ubuntu 8.10 'Intrepid Ibex' (see Ubuntu 8.10 'Intrepid Ibex' upgrades and Ubuntu 8.10 'Intrepid Ibex' update. In the second of those postings, I reported that an attempt to project from my laptop borked all my nice Compiz desktop effects.
This morning I made one last ditch attempt to resolve this before reinstalling 8.10 - and succeeded. This was in part due to advice in this thread at ubuntuforums.org.