I have a Dell E521 and I have iDeneb 10.5.5 (I think) installed just fine, I tried to upgrade to iDeneb 10.5.6 and my system won't boot off the dvd (I know the dvd is good, my laptop boots off it just fine). I tried Leo4All, sam media errors, finally, iPC work, I reboot -f -v, setup my EFI string and the mouse goes wonkers. If I boot without EFI/NVinject/CoeVidia settings for my 8800gt, the mouse is fine.

I have tried deleting the Upstream, no joy. I think it has something to do with the video somehow, I intend to go back to 10.5.2 (my 10.5.5 cd is now mia) and try to upgrade up.

Dual Core AMD Athlon 64 x2 3800+
Nvidia GeForce 8800 GT 512MB
4gb RAM
SATA HD & DVD