Unity displays the wallpaper after an unresponsive delay

[tuuk]

Since I have upgraded from 12.10 to 13.04 (a few weeks ago), I have been having some annoying behaviour after login. First of all, the wallpaper does not come on, instead the login screen is continued to be displayed as a background, together with slow appearing top panel and Unity launcher. Secondly, the UI is unresponsive for a minute or so, while there is a lot of disk activity. Switching to console (Ctrl+Al+F1) and running 'top', I see ubuntuone sync deamon (and sometimes gnote which is set up to open a note at login) are taking some CPU time (sometimes 90+%). After a while, it turns to normal and the selected wallpaper appears.

I see some problems reported about wallpapers after upgrading to 13.04; none seems to match my situation or provide any solutions that work.

There was an error message during my upgrade to 13.04, about missing or mislocated items related to gnome (I think word 'icons' appeared in the path from the error message).

My system is a Dell Latitude E6510 laptop with Intel graphics.

[gordintoronto]

This is a long shot: run the program Disks, point at your hard drive, look at the Smart data, is your hard drive healthy?