I think that was from too many icons/widgets? (rhetorical)
Anyway, removing icons/widgets should speed it up or just get a different launcher from the playstore. If there is a setting that fixes it I don't know.
If you using the latest cm10.2 I'm surprised that problem occurs.
HTC sensation 4G | cm11 albinoman ROM - 3/2/14 Workaround for incoming phone calls going to missed (including the swipe issue) with all cm based roms -> http://forum.xda-developers.com/show...&postcount=884
(Longest recorded uptime: 1,060 hours)
Nook HD+ 32 | cm11 emmc official ROM (Longest recorded uptime: 331 hours with much daily use)
....Nook HD+ 16 | (Returned due to random reboots; defective tablet)