Default [Q] scheduled tasks problems

I have a rooted GT-19300 running android version 4.2.2 with Touchwiz as the home screen/launcher on Vodafone UK. Over the past 2 weeks I have had a problem with using programmes which schedule activities - Titanium Backup Pro, and sound profiles. They all work fine if I run them, but scheduled activities set and then seem to disappear before the time they should work, and so I am having to set them manually. This wasn't a problem just 2 or 3 weeks ago, and I am not aware of any changes that could have caused these problems. I even changed the sound profile programme (from Profile Scheduler to Sound Profile) to see if that solved the problem - it did not. That makes me think it is either a software interaction or an os problem, but don't understand why it suddenly stopped working. Any help appreciated.