HTC One S vibration keeps getting turned on for normal profile I have a HTC One S with stock ROM (latest update) and stock launcher, no root or anything. Android is 4.0.4 ICS. HTC Sense 4.1. In sound settings, for the normal sound profile, I turn vibration for calls/messages/notifications off, but after some time it mysteriously comes back.

I don't know what triggers it. It happens after switching profiles a couple of times, like switching to vibrate profile and later switching back to normal. I have a suspicion that it might be related to using the physical volume up/down button to switch the profile. I usually use the stock 1x1 HTC widget to switch between profiles. It kind of annoys me and I consider it a bug. Does enyone experience the same? How can I prevent it?

Update: it just happened again after a system crash. I'm getting these more frequently lately, and after every crash the vibration is back. I can now list this as a confirmed trigger, but I'm not sure if it's the only one.
In my ICS (on LG Swift hardware) the switch to "ring" profile occured on every answered call during daytime. Somebody else at Polish LG forum complained about switching to "quiet" at night. 

SOLVED: After some reading and a simple experiment I found that it is the system app to switch profiles for the nighttime (settings->sounds->"silence time" in my LG). This is a buggy app: after any event requiring sound on - like answered call or so -- it switches to the scheduled profile, even if it was overriden manually.

To make clear: I have "nighttime" quiet setting, so after manual switch to "loud", upon first call it automatically returns to "quiet". In the daytime, when quietened manually, after a first call it returns to "loud".

Switching this option off helps.

P.S. I have read about problems with tasker after upgrade - maybe it is some more general bug (or feature making some apps incompatible)