when resume from suspend, my desktop went frozen

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http://askubuntu.com – I can move my mouse around, see wall paper and top panel or switch to ctrl-alt-F1. But I cannot click anything nor do any key combination work. What should I do beside restart lightdm? I chose to suspend because I don't want to lose my data. If I have to restart lightdm every time resume from suspend, I'd rather shutdown my computer. how can i get normal suspend functionality back? (HowTos)