Since you are jailbroken, it's likely a badly behaving tweak. Either disable them one by one using SBSetting > More > Mobile Substrate Addons, to find the culprit yourself, or list them all out here and we will see if we can spot what might be the problem...
actionmenu
applist
apr-lib
apt
apt7
apt7-key
apt7-lib
apt7-ssl
base
bash
berkeleydb
bzip2
com.aakasht.quickmemo
com.chpwn.iconsupport
com.chpwn.weeloader
com.chronic-dev.greenpois0n.rocky-racoon
com.ericasadun.utilities
com.fabius.utils
com.filippobiga.passwordpilot
com.filippobiga.springtomize2-icons
com.filippobiga.springtomize2-localizations
com.jmeosbn.simplealert
com.justinxxvii.datadepositapp
com.modmyi.serioussbsettingshd
com.moritz.eyeoz.datamonitor
com.mxweas.mxtube
com.nakedproductions.inorotate
com.nickf.anylockapp
com.orikad.chromizer
com.phoenix.bars
com.phoenix.resupported4
com.rpetrich.layersnapshotter
com.saurik.iphone.ske
com.saurik.substrate.safemode
com.sbsdefaulthdtheme
com.w00tylab.ncquickdismiss
com.zimm.libdisplaystack
com.zokunei.openbackup
coreutils
coreutils-bin
curl
cy+cpu.arm
cy+kernel.darwin
cy+lib.corefoundation
cy+model.iphone
cy+os.ios
cycript
cydget
cydia
cydia-lproj
darwintools
debianutils
diffutils
diskdev-cmds
dpkg
facetime-hacktivator
file-cmds
findutils
firmware
firmware-sbin
gcrypt
gdata-objectivec-client
gnupg
grep
gzip
jp.ashikase.bugfix.duplicateicons
jp.ashikase.bugfix.stuckpages
jp.ashikase.mousesupport
jp.ashikase.multiiconmover
jp.tom-go.openopera
jpeg
libactivator
libffi
libgpg-error
libhide
libid3tag
libstatusbar
libvncserver
libxml2
libxml2-lib
libzip
lzma
me.devbug.swipenav
me.k3a.libaiml
mobi.macciti.cydiasearchnc
mobi.macciti.respringios5
mobilesubstrate
ncurses
net.howett.cydelete
openssh
openssl
org.thebigboss.customwidgeticons
org.thebigboss.iconmaker
org.thebigboss.repo.icons
org.thebigboss.sbsairplanetoggle
p7zip
pam
pam-modules
pcre
preferenceloader
profile.d
readline
sandcastle
sbsettings
sbsettingstoggles
sed
shell-cmds
system-cmds
tar
uikittools
unrar
unzip
veency
zip