So my phone worked perfectly fine until I installed the most recent software update. After this, the phone no longer vibrates when it is in vibrate mode. The haptic feedback still works perfectly, and when I switch it to vibrate the phone buzzes, but when I get a text it doesn't vibrate. I don't have any fancy features installed or anything, so it's probably not that. I tried clearing the applications cache (whatever that is) but that didn't help at all.