Sometimes my phone hangs up and stay unresponsive for upto 1-2 minutes when i kill some apps from appswitcher although I am not using any tweak to kill background apps. Here is the list of my tweaks installed on my iphone to provide some more details.
Activator
Action Menu
Aloud
Barrel
BiteSMS
Bytafont
CleanStatus
GPowerPro
IntelliScreenx
ManualCorrect
MapReminders
PhyScroll
PkgBackup
PullToDismiss
SBSettings
ScrollinngBoard
SpringFlash
Springtomize2 (I doubt this may be causing this problem)
SwipeShiftCaret
Unfold
VMK+Groups
WeatherIcon
Weeslide for Notification Centre
Zephyr
Zeppelin
Activator
Action Menu
Aloud
Barrel
BiteSMS
Bytafont
CleanStatus
GPowerPro
IntelliScreenx
ManualCorrect
MapReminders
PhyScroll
PkgBackup
PullToDismiss
SBSettings
ScrollinngBoard
SpringFlash
Springtomize2 (I doubt this may be causing this problem)
SwipeShiftCaret
Unfold
VMK+Groups
WeatherIcon
Weeslide for Notification Centre
Zephyr
Zeppelin