When booting F19 x64 Gnome often hangs...

[Roger]

Have you noticed that Fedora 19 also hangs if there are several windows 
and terminals open.

I often have Nautilus, at least 2 terminals, geany and chrome and 
sometimes firefox open and intermittently everything except mouse stops.
top still functions and is uninformative and there's nothing in 
/var/log/messages, system monitor shows nothing untoward, 60%memory, 
cpus running between 60 and 80%.

Oh I'm using cinnamon not gnome3.
I have to click on the X shut down button (top right corner) on each 
window and terminal till I find one that closes,  because the keyboard 
is also locked, close all and reopen again, all is normal for some time 
till it locks again.
This is the first Fedora where I have experienced this problem.
Roger