I've been getting this exact same problem.
I initially thought it was related to "libstatusbar" as I had a few issue with it since that was updated, however libstatusbar has now had a further 2 updates and I'm still finding my phone to freeze on the lock screen.
I've already tried removing and reinstalling both IntelliscreenX as well as Libstatusbar to no avail.
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Copied from intelliborn support site
IntelliScreenX is crashing - please help!
We have done extensive testing with IntelliScreenX - however, because the jailbreak community works in shared processes, conflicts with other applications may occur.
We kindly ask you remove all other extensions for MobileSubstrate and only install IntelliScreenX to troubleshoot. If it crashes, we'd love a crash report and are VERY committed to fixing any crashes immediately.
If the problem occurs after installing another library, we will work with the developer of the other product to help resolve how to fix it.
We greatly appreciate your patience on helping resolve issues as they arise!
Known Conflicts
Currently, there is one known crash conflict, which is Barrel. Currently - the work around is to disable "Experimental FolderEnhancer Fix" in Barrel Settings under Preferences.
Now I use folder enhancer on my phone so to test I've disabled that and will see if I still get the issue. Will report back if it does.