I had the same intermittent issue on my Dell laptop. I am booting 12.10 x64 from a SSD drive. Starting with 12.10, the boot time has improved significantly and apparently that is part of the problem. I experimented with placing a service lightdm restart in rc.local but that resulted in a non-functioning touchpad. Michael's tip (#16) works perfectly for me.
I had the same intermittent issue on my Dell laptop. I am booting 12.10 x64 from a SSD drive. Starting with 12.10, the boot time has improved significantly and apparently that is part of the problem. I experimented with placing a service lightdm restart in rc.local but that resulted in a non-functioning touchpad. Michael's tip (#16) works perfectly for me.
Thanks, Michael!