If it was my problem I'd google it haha. But i haven't upgraded to ios 8.1 yet, and there are some people here who have knowledge in this aspect.
Besides, Most articles you find on google are written by retarded people. Although i could probably find something about this topic
Downgrade from iOS 8.1 to 7? My computer teacher pulled me to the side today and asked me which i have no knowledge in but i got curious. He said as soon as he installed 8.1 his phone turned to complete shit.